biology chapter 2 part 1
TRANSCRIPT
862019 Biology Chapter 2 Part 1
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Molecules of Life
Chapter 2
Part 1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 289
21 ImpactsIssues
Fear of Frying
All living things consist of the same kinds of
molecules but small differences in the waysthey are put together have big effects on health
Artificial trans fats found in manufactured and
fast foods raise cholesterol and increase risk of
atherosclerosis heart attack and diabetes
862019 Biology Chapter 2 Part 1
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Video Fear of frying
862019 Biology Chapter 2 Part 1
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Fear of Frying
Trans fats are made by adding hydrogen atomsto liquid vegetable oils
862019 Biology Chapter 2 Part 1
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Fig 2-1 p 20
trans fatty acid
862019 Biology Chapter 2 Part 1
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22 Start With Atoms
All substances consist of atoms
Atom
bull Fundamental building-block particle of matter
Lifersquos unique characteristics start with the
properties of different atoms
862019 Biology Chapter 2 Part 1
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Subatomic Particles and Their Charge
Atoms consist of electrons moving around anucleus of protons and neutrons
Electron (e-
) bull Negatively charged subatomic particle that
occupies orbitals around the atomic nucleus
Charge
bull Electrical property of some subatomic particles
bull Opposite charges attract like charges repel
862019 Biology Chapter 2 Part 1
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Subatomic Particles in the Nucleus
Nucleusbull Core of an atom occupied by protons and
neutrons
Proton (p+)bull Positively charged subatomic particle found in the
nucleus of all atoms
Neutronbull Uncharged subatomic particle found in the atomic
nucleus
862019 Biology Chapter 2 Part 1
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An Atom
862019 Biology Chapter 2 Part 1
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an atom
862019 Biology Chapter 2 Part 1
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
862019 Biology Chapter 2 Part 1
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Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
862019 Biology Chapter 2 Part 1
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Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
862019 Biology Chapter 2 Part 1
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
862019 Biology Chapter 2 Part 1
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
862019 Biology Chapter 2 Part 1
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
862019 Biology Chapter 2 Part 1
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
862019 Biology Chapter 2 Part 1
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Shell Models
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2289Fig 2-3 (a-c) p
Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
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Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
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Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
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Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
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Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
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Animation Electron distribution
862019 Biology Chapter 2 Part 1
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
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Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
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An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
862019 Biology Chapter 2 Part 1
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p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
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Animation Ionic bonding
862019 Biology Chapter 2 Part 1
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Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
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Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
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Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
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Animation Covalent bonds
862019 Biology Chapter 2 Part 1
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
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Unique Properties of Water
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
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Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
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Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
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Animation Structure of water
862019 Biology Chapter 2 Part 1
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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862019 Biology Chapter 2 Part 1
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
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Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
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Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
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Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
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Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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21 ImpactsIssues
Fear of Frying
All living things consist of the same kinds of
molecules but small differences in the waysthey are put together have big effects on health
Artificial trans fats found in manufactured and
fast foods raise cholesterol and increase risk of
atherosclerosis heart attack and diabetes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 389
Video Fear of frying
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 489
Fear of Frying
Trans fats are made by adding hydrogen atomsto liquid vegetable oils
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 589
Fig 2-1 p 20
trans fatty acid
862019 Biology Chapter 2 Part 1
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22 Start With Atoms
All substances consist of atoms
Atom
bull Fundamental building-block particle of matter
Lifersquos unique characteristics start with the
properties of different atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 789
Subatomic Particles and Their Charge
Atoms consist of electrons moving around anucleus of protons and neutrons
Electron (e-
) bull Negatively charged subatomic particle that
occupies orbitals around the atomic nucleus
Charge
bull Electrical property of some subatomic particles
bull Opposite charges attract like charges repel
862019 Biology Chapter 2 Part 1
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Subatomic Particles in the Nucleus
Nucleusbull Core of an atom occupied by protons and
neutrons
Proton (p+)bull Positively charged subatomic particle found in the
nucleus of all atoms
Neutronbull Uncharged subatomic particle found in the atomic
nucleus
862019 Biology Chapter 2 Part 1
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An Atom
862019 Biology Chapter 2 Part 1
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an atom
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
862019 Biology Chapter 2 Part 1
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Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
862019 Biology Chapter 2 Part 1
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Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
862019 Biology Chapter 2 Part 1
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
862019 Biology Chapter 2 Part 1
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
862019 Biology Chapter 2 Part 1
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Shell Models
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2489
Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
862019 Biology Chapter 2 Part 1
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
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Animation The pH scale
A id R i
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
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Video Fear of frying
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Fear of Frying
Trans fats are made by adding hydrogen atomsto liquid vegetable oils
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Fig 2-1 p 20
trans fatty acid
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22 Start With Atoms
All substances consist of atoms
Atom
bull Fundamental building-block particle of matter
Lifersquos unique characteristics start with the
properties of different atoms
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Subatomic Particles and Their Charge
Atoms consist of electrons moving around anucleus of protons and neutrons
Electron (e-
) bull Negatively charged subatomic particle that
occupies orbitals around the atomic nucleus
Charge
bull Electrical property of some subatomic particles
bull Opposite charges attract like charges repel
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Subatomic Particles in the Nucleus
Nucleusbull Core of an atom occupied by protons and
neutrons
Proton (p+)bull Positively charged subatomic particle found in the
nucleus of all atoms
Neutronbull Uncharged subatomic particle found in the atomic
nucleus
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An Atom
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an atom
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
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Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
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Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
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Fig 2-7b p 26
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Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
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Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
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Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
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Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
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Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 489
Fear of Frying
Trans fats are made by adding hydrogen atomsto liquid vegetable oils
862019 Biology Chapter 2 Part 1
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Fig 2-1 p 20
trans fatty acid
862019 Biology Chapter 2 Part 1
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22 Start With Atoms
All substances consist of atoms
Atom
bull Fundamental building-block particle of matter
Lifersquos unique characteristics start with the
properties of different atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 789
Subatomic Particles and Their Charge
Atoms consist of electrons moving around anucleus of protons and neutrons
Electron (e-
) bull Negatively charged subatomic particle that
occupies orbitals around the atomic nucleus
Charge
bull Electrical property of some subatomic particles
bull Opposite charges attract like charges repel
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 889
Subatomic Particles in the Nucleus
Nucleusbull Core of an atom occupied by protons and
neutrons
Proton (p+)bull Positively charged subatomic particle found in the
nucleus of all atoms
Neutronbull Uncharged subatomic particle found in the atomic
nucleus
862019 Biology Chapter 2 Part 1
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An Atom
862019 Biology Chapter 2 Part 1
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an atom
862019 Biology Chapter 2 Part 1
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1289
Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1389
Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1489
Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
862019 Biology Chapter 2 Part 1
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1689
Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1789
Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
862019 Biology Chapter 2 Part 1
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Shell Models
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
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Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
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Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
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Animation Ionic bonding
862019 Biology Chapter 2 Part 1
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Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
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Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
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Unique Properties of Water
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862019 Biology Chapter 2 Part 1
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
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Fig 2-7b p 26
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Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
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Animation Structure of water
862019 Biology Chapter 2 Part 1
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 589
Fig 2-1 p 20
trans fatty acid
862019 Biology Chapter 2 Part 1
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22 Start With Atoms
All substances consist of atoms
Atom
bull Fundamental building-block particle of matter
Lifersquos unique characteristics start with the
properties of different atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 789
Subatomic Particles and Their Charge
Atoms consist of electrons moving around anucleus of protons and neutrons
Electron (e-
) bull Negatively charged subatomic particle that
occupies orbitals around the atomic nucleus
Charge
bull Electrical property of some subatomic particles
bull Opposite charges attract like charges repel
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 889
Subatomic Particles in the Nucleus
Nucleusbull Core of an atom occupied by protons and
neutrons
Proton (p+)bull Positively charged subatomic particle found in the
nucleus of all atoms
Neutronbull Uncharged subatomic particle found in the atomic
nucleus
862019 Biology Chapter 2 Part 1
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An Atom
862019 Biology Chapter 2 Part 1
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an atom
862019 Biology Chapter 2 Part 1
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1289
Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1389
Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1489
Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1689
Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1789
Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
862019 Biology Chapter 2 Part 1
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Shell Models
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
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Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
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Animation The pH scale
A id R i
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
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22 Start With Atoms
All substances consist of atoms
Atom
bull Fundamental building-block particle of matter
Lifersquos unique characteristics start with the
properties of different atoms
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Subatomic Particles and Their Charge
Atoms consist of electrons moving around anucleus of protons and neutrons
Electron (e-
) bull Negatively charged subatomic particle that
occupies orbitals around the atomic nucleus
Charge
bull Electrical property of some subatomic particles
bull Opposite charges attract like charges repel
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Subatomic Particles in the Nucleus
Nucleusbull Core of an atom occupied by protons and
neutrons
Proton (p+)bull Positively charged subatomic particle found in the
nucleus of all atoms
Neutronbull Uncharged subatomic particle found in the atomic
nucleus
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An Atom
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an atom
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
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Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
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Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
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httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
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Animation The pH scale
A id R i
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
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Subatomic Particles and Their Charge
Atoms consist of electrons moving around anucleus of protons and neutrons
Electron (e-
) bull Negatively charged subatomic particle that
occupies orbitals around the atomic nucleus
Charge
bull Electrical property of some subatomic particles
bull Opposite charges attract like charges repel
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Subatomic Particles in the Nucleus
Nucleusbull Core of an atom occupied by protons and
neutrons
Proton (p+)bull Positively charged subatomic particle found in the
nucleus of all atoms
Neutronbull Uncharged subatomic particle found in the atomic
nucleus
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An Atom
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an atom
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
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Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
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Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
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Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 889
Subatomic Particles in the Nucleus
Nucleusbull Core of an atom occupied by protons and
neutrons
Proton (p+)bull Positively charged subatomic particle found in the
nucleus of all atoms
Neutronbull Uncharged subatomic particle found in the atomic
nucleus
862019 Biology Chapter 2 Part 1
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An Atom
862019 Biology Chapter 2 Part 1
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an atom
862019 Biology Chapter 2 Part 1
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1289
Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1389
Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1489
Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1589
Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1689
Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1789
Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
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httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2189Fig 2-3 (a-c) p
1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
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Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
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Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
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Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
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Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
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Animation Electron distribution
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httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
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Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
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Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
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Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 989
An Atom
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1089Fig 2-2a p 21
an atom
862019 Biology Chapter 2 Part 1
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1289
Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1389
Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
862019 Biology Chapter 2 Part 1
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
862019 Biology Chapter 2 Part 1
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
862019 Biology Chapter 2 Part 1
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1789
Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
862019 Biology Chapter 2 Part 1
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Shell Models
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
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Animation The pH scale
A id R i
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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an atom
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Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
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Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
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Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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862019 Biology Chapter 2 Part 1
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
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Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
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Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
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Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
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Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1189
Elements Different Types of Atoms
Atoms differ in numbers of subatomic particles
Elementbull A pure substance that consists only of atoms with
the same number of protons
Atomic number
bull Number of protons in the atomic nucleus
bull Determines the element
862019 Biology Chapter 2 Part 1
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Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
862019 Biology Chapter 2 Part 1
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Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1489
Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
862019 Biology Chapter 2 Part 1
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1689
Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1789
Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
862019 Biology Chapter 2 Part 1
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Shell Models
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
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Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
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Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
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Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
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Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
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Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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Elements in Living Things
The proportions of different elements differ
between living and nonliving things
Some atoms such as carbon are found in
greater proportions in molecules made only by
living things ndash the molecules of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1389
Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
862019 Biology Chapter 2 Part 1
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
862019 Biology Chapter 2 Part 1
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
862019 Biology Chapter 2 Part 1
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1789
Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
862019 Biology Chapter 2 Part 1
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Shell Models
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
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Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
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Same Elements Different Forms
Isotopes
bull Forms of an element that differ in the number of
neutrons their atoms carry
bull Changes the mass number but not the charge
Mass number
bull Total number of protons and neutrons in thenucleus of an elementrsquos atoms
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
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Unique Properties of Water
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862019 Biology Chapter 2 Part 1
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
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Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
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Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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Radioactive Isotopes
Radioisotope
bull Isotope with an unstable nucleus such as
carbon 14 (
14
C)
Radioactive decay
bull Process by which atoms of a radioisotope
spontaneously emit energy and subatomicparticles when their nucleus disintegrates
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
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Animation The pH scale
A id R i
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
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Carbon 14 A Radioisotope
Most carbon atoms have 6 protons and 6
neutrons (12C)
Carbon 14 (14C) is a radioisotope with six protons
and eight neutrons
When 14C decays one neutron splits into a
proton and an electron and the atom becomes a
different element ndash nitrogen 14 (14N)
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
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Animation The pH scale
A id R i
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
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Radioactive Tracers
Researchers introduce radioisotope tracers into
living organisms to study the way they move
through a system
Tracers
bull Molecules with a detectable substance attached
often a radioisotope
bull Used in research and clinical testing
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
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Animation The pH scale
A id R i
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
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Why Electrons Matter
Electrons travel around the nucleus in different
orbitals (shells) ndash atoms with vacancies in their
outer shells tend to interact with other atoms
bull Atoms get rid of vacancies by gaining or losing
electrons or sharing electrons with other atoms
Shell modelbull Model of electron distribution in an atom
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Shell Models
862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
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Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
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Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
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Animation Electron distribution
862019 Biology Chapter 2 Part 1
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
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Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
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An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
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p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
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Unique Properties of Water
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
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Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
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Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
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Shell Models
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2089Fig 2-3 (a-c) p 22
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2189Fig 2-3 (a-c) p
1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
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Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
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Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
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Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
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Animation Electron distribution
862019 Biology Chapter 2 Part 1
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
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An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
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Animation Sucrose synthesis
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httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
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Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
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Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
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Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
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Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 1989Fig 2-3 (top) p 22
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
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Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
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An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
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p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
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Animation Ionic bonding
862019 Biology Chapter 2 Part 1
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
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Unique Properties of Water
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
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Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
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Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
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Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2089Fig 2-3 (a-c) p 22
862019 Biology Chapter 2 Part 1
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1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
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Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
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Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
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Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
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Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
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Animation Electron distribution
862019 Biology Chapter 2 Part 1
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
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Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
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An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
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p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
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p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
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Animation Ionic bonding
862019 Biology Chapter 2 Part 1
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
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Unique Properties of Water
862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
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Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
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Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
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Animation Structure of water
862019 Biology Chapter 2 Part 1
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
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A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
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Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
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Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
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Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
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Video ABC News Bottle Backlash
Video ABC News Water Use
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Video ABC News Water Use
Video ABC News Water Wars
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2189Fig 2-3 (a-c) p
1 proton 1 2
1 electronfirst shell hydrogen (H) helium (He)
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
862019 Biology Chapter 2 Part 1
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Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
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Ion Formation
electron Chl i
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
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Animation The shell model of electron
distribution
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Animation Subatomic particles
Animation Atomic number mass
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
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Animation Isotopes of hydrogen
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Video ABC News Nuclear Energy
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Animation Electron distribution
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
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Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
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Animation Building blocks of life
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Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
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p 25
hydrogen bond
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Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
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Animation Ionic bonding
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Animation Examples of hydrogen bonds
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Video ABC News Fuel Cell Vehicles
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Animation Sucrose synthesis
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Animation Covalent bonds
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24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
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Unique Properties of Water
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Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
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Fig 2-7b p 26
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Fig 2-7c p 26
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Animation Structure of water
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Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
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Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
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Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
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Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
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862019 Biology Chapter 2 Part 1
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862019 Biology Chapter 2 Part 1
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Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
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httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
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Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
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Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
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Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
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Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
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Video ABC News Water Wars
3D Animation Dissolution
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3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2289Fig 2-3 (a-c) p
Stepped Art
1 proton 1 2
1 electron
first shell hydrogen (H) helium (He)
A) The first shell corresponds to
the first energy level and it can
hold up to 2 electrons Hydrogen
has one proton so it has one
vacancy A helium atom has 2
protons and no vacancies The
number of protons in each shellmodel is shown
6 8 10
second shell carbon (C) oxygen (O) neon (Ne)
B) The second shell corresponds
to the second energy level and it
can hold up to 8 electrons Carbon
has 6 protons so its first shell is
full Its second shell has 4
electrons and four vacancies
Oxygen has 8 protons and two
vacancies Neon has 10 protons
and no vacancies
11 17 18
third shell sodium (Na) chlorine (Cl) argon (Ar)
C) The third shell which
corresponds to the third energylevel can hold up to 8 electrons
for a total of 18 A sodium atom
has 11 protons so its first two
shells are full the third shell has
one electron Thus sodium has
seven vacancies Chlorine has 17
protons and one vacancy Argon
has 18 protons and no vacancies
A i ti Sh ll d l f
862019 Biology Chapter 2 Part 1
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Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
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Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
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Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
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Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
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Fig 2-4a p 23
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Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
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Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
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Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
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Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
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Animation How atoms bond
862019 Biology Chapter 2 Part 1
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Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
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Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
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Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
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Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
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Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
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Animation Electron distribution
862019 Biology Chapter 2 Part 1
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23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
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From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
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Referring to a Molecule
862019 Biology Chapter 2 Part 1
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Same Materials Different Results
862019 Biology Chapter 2 Part 1
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Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
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An Ionic Bond Sodium Chloride
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p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
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Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
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p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
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Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
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Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
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Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
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p 25
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p 25
1 8 1
water (H2O)
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httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2389
Animation Shell models of common
elements
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2489
Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2589
Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2689
Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2789
Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2889
Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2989
Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3089
Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3189
Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2489
Ions
The negative charge of an electron balances the
positive charge of a proton in the nucleus
Changing the number of electrons may fill its
outer shell but changes the charge of the atom
Ion
bull Atom that carries a charge because it has an
unequal number of protons and electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2589
Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2689
Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2789
Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2889
Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2989
Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3089
Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3189
Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2589
Ion Formation
electron Chl i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2689
Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2789
Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2889
Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2989
Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3089
Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3189
Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2689
Fig 2-4 p 23
electron
loss
Sodiumatom
1111p+
11e ndash
charge 0
Sodiumion
11p+11
charge +110e
ndash
electron
gainChlorineatom
17 17p+
17e ndash
charge 0
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2789
Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2889
Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2989
Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3089
Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3189
Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2789
Fig 2-4a p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2889
Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2989
Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3089
Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3189
Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2889
Fig 2-4a p 23
electron
gain Chlorine
atom
17 17p+
17e ndash
charge 0
Chloride
ion
18e ndash1717p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2989
Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3089
Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3189
Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 2989
Fig 2-4b p 23
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3089
Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3189
Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3089
Fig 2-4b p 23
electron
loss Sodium
atom
11 11p+
11e ndash
charge 0
Sodium
ion
11p+11
charge +1
10e ndash
Chlorineelectron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3189
Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3189
Fig 2-4 p 23
Sodiumatom
1111p+
11e ndash
charge 0
electron
loss
Sodiumion
11p+11
charge +110e
ndash
Stepped Art
Chlorineatom
17 17p+
17e ndash
charge 0
electron
gain
Chlorideion
18e ndash
17 17p+
charge ndash1
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3289
Animation How atoms bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3389
Animation PET scan
Animation The shell model of electron
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3489
Animation The shell model of electron
distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3589
Animation Subatomic particles
Animation Atomic number mass
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3689
Animation Atomic number mass
number
Animation Electron arrangements in
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3789
Animation Electron arrangements in
atoms
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3889
Animation Isotopes of hydrogen
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 3989
Video ABC News Nuclear Energy
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4089
Animation Electron distribution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4189
23 From Atoms to Molecules
Atoms can also fill their vacancies by sharing
electrons with other atoms
A chemical bond forms when the electrons of
two atoms interact
Chemical bond
bull An attractive force that arises between two atoms
when their electrons interact
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4289
From Atoms to Molecules
Molecule
bull
Group of two or more atoms joined by chemicalbonds
Compound
bull Type of molecule that has atoms of more than
one element
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4389
Referring to a Molecule
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4489
Same Materials Different Results
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4589
Animation Building blocks of life
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4689
Ionic Bonds and Covalent Bonds
Depending on the atoms a chemical bond may
be ionic or covalent
Ionic bond
bull A strong mutual attraction formed between ions of
opposite charge
Covalent bond
bull Two atoms sharing a pair of electrons
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4789
An Ionic Bond Sodium Chloride
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4889
p 24
ionic bond
11 17
sodium ion (Na+) chloride ion (Cl ndash)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 4989
Covalent Bonds
Molecular hydrogen (HmdashH) and molecular oxygen (O=O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5089
p 24
1 1
molecular hydrogen (H2)
8 8
molecular oxygen (O2)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5189
Polarity
A covalent bond is nonpolar if electrons are
shared equally and polar if the sharing is unequal
Polarity
bull Any separation of charge into distinct positive and
negative regions
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5289
Polar and Nonpolar Covalent Bonds
Nonpolar
bull Having an even distribution of charge
bull When atoms in a covalent bond share electrons
equally the bond is nonpolar
Polar
bull Having an uneven distribution of chargebull When the atoms share electrons unequally the
bond is polar
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5389
Importance of Polar Molecules
A water molecule (H-O-H) has two polar
covalent bonds ndash the oxygen is slightly negative
and the hydrogens are slightly positive ndash which
allows water to form hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5489
p 25
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5589
p 25
1 8 1
water (H2O)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5689
Hydrogen Bonds
Hydrogen bond
bull Attraction that forms between a covalently
bonded hydrogen atom and another atom taking
part in a separate covalent bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5789
p 25
hydrogen bond
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5889
Importance of Hydrogen Bonds
Hydrogen bonds form and break more easily
than covalent or ionic bonds ndash they do not form
molecules
Hydrogen bonds impart unique properties to
substances such as water and hold moleculessuch as DNA in their characteristic shapes
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 5989
Animation Ionic bonding
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6089
Animation Examples of hydrogen bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6189
Video ABC News Fuel Cell Vehicles
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6289
Animation Sucrose synthesis
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6389
Animation Covalent bonds
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6489
24 Water
All living organisms are mostly water and all
chemical reactions of life are carried out in water
Hydrogen bonds between water molecules give
water unique properties that make life possible
bull Capacity to dissolve many substances
bull Cohesion (surface tension)
bull Temperature stability
Polarity and the
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6589
Unique Properties of Water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6789
Fig 2-7a p 26
slight negative charge
slight positive charge slight positive charge
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6889
Fig 2-7b p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 6989
Fig 2-7c p 26
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7089
Animation Structure of water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7189
Water and Solutions
Polar water molecules hydrogen-bond to other
polar (hydrophilic) substances and repel
nonpolar (hydrophobic) substances
Hydrophilic (water-loving)
bull A substance that dissolves easily in water
Hydrophobic (water-dreading)
bull A substance that resists dissolving in water
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7289
Water and Solutions
Water is an excellent solvent
Solventbull Liquid that can dissolve other substances
Solute
bull A dissolved substance
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7389
Water and Solutions
Salts sugars and many polar molecules
dissolve easily in water
Salt
bull Compound that dissolves easily in water and
releases ions other than H+ and OH-
bull Example sodium chloride (NaCl)
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7489
Water and Solutions
Water molecules surround the atoms of an ionicsolid and pull them apart dissolving it
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7589
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7689
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7789
Cohesion
Cohesion helps sustain multicelled bodies and
resists evaporation
Cohesion
bull Tendency of water molecules to stick together
Evaporation
bull Transition of liquid to gas
bull Absorbs heat energy (cooling effect)
2 A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7889
25 Acids and Bases
Water molecules separate into hydrogen ions(H+) and hydroxide ions (OH-)
pH
bull A measure of the number of hydrogen ions (H+) in
a solution
bull The more hydrogen ions the lower the pH
Pure water has neutral pH (pH=7)
bull Number of H+ ions = OH- ions
A id d B
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 7989
Acids and Bases
Acid
bull Substance that releases hydrogen ions in water
bull pH less than 7
Base
bull Substance that releases hydroxide ions (accepts
hydrogen ions) in water
bull pH greater than 7
A H S l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8089
A pH Scale
mdash 0 battery acid
mdash 1 gastric fluid
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8189
Fig 2-9 p 27
g
lemon juicemdash 2acid rain
cola
mdash 3vinegar
more
acid
ic
tomatoeswine
orange juice
mdash 4 bananas
beer
mdash 5 black coffeebread
urine tea typical rain
butter mdash 6 corn
milk
mdash 7pure water
mdash 8 seawater egg whiteblood tears
mdash 9 detergentsbaking soda
Tums
mdash 10hand soaptoothpaste
milk of magnesia
household ammoniamdash 11
morebas
ic
mdash 12 hair remover
bleachmdash 13
mdash 14 drain cleaner
oven cleaner
A i ti Th H l
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8289
Animation The pH scale
A id R i
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8389
Acid Rain
Sulfur dioxide and other airborne pollutantsdissolve in water vapor to form acid rain
B ff S t
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8489
Buffer Systems
Most molecules of life work only within a narrowrange of pH ndash essential for homeostasis
Buffers keep solutions in cells and tissues withina consistent range of pH
Buffer bull Set of chemicals that can keep the pH of a
solution stable by alternately donating andaccepting ions that contribute to pH
CO and the Bicarbonate Buffer System
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8589
CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
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CO2 and the Bicarbonate Buffer System
CO2forms carbonic acid in water
bull CO2+ H
2O rarr H
2CO
3(carbonic acid)
Bicarbonate buffer system
bull Excess H+ combines with bicarbonate
bull H+ + HCO3
- (bicarbonate) harr H2CO
3
Vid ABC N B ttl B kl h
862019 Biology Chapter 2 Part 1
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Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8689
Video ABC News Bottle Backlash
Video ABC News Water Use
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8789
Video ABC News Water Use
Video ABC News Water Wars
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8889
Video ABC News Water Wars
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution
862019 Biology Chapter 2 Part 1
httpslidepdfcomreaderfullbiology-chapter-2-part-1 8989
3D Animation Dissolution