chemistry of lif
TRANSCRIPT
the basics
• Every living and nonliving things is
made up of matter
• MATTER: anything that has mass &
takes up space
What does all matter have in common?
• Smallest unit of matter – ALL matter is made of
particles called atoms
• Always in motion and bumping into each other – Kinetic energy – the
energy of motion
• Have a definite shape & volume
• Molecules are packed tightly together
in a pattern
• DO move – more of a vibration
• Have a definite volume but NO
definite shape
– Not in any arrangement
• Molecules are loosely packed and
flow against each other
– loosey goosey = loosey liquids
• Have no definite shape and no
definite volume
– Not in any arrangement
• Molecules are far apart and can move
freely
Matter either looses or absorbs energy when it changes states
• Solid liquid = melting
• Solid gas = sublimation
• Liquid solid = freezing
• Liquid gas = vaporization
• Gas liquid = condensation
• Gas solid = deposition
• Two major parts
– Nucleus
• Positively charged
– Electron cloud • Negatively
charged
• Proton – Positively charged
– Found in nucleus
– The # of these determines the elements
– Contributes to mass
• Neutrons – No charge – neutral
– Found in nucleus
– Contributes to mass
+ o
• Electron
– Negatively charges
– Located in electron
cloud
– So small contribute
very little mass
– The outer most
electrons are used
in bonding
(valence electrons)
• A substance made up of atoms that all
have the same number of protons
• CAN NOT be broken down into simpler
substances
– EX: Gold & Oxygen
• Arrangement of elements ordered
by:
–Atomic number
–Electron configuration
–Chemical properties
• Element name – Unique for each element
– Usually from Latin based words due to ancient Romans attempting to identify elements
– Sometimes named after scientists who discovered them (ego much?) • Must be approved by committee
• Element symbol – Some names are longggg or hard to
pronounce
– Some based on name of element others are based in different language
– First letter is ALWAYS capitalized
12
24.305
Magnesium
Mg
• Atomic number – The number of protons found in
the nucleus
• Atomic mass – The total mass of all the protons
& neutrons • Each proton & each neutron are
equal to 1 AMU (atomic mass unit
atomic mass – atomic number = # of neutrons
12
24.305
Magnesium
Mg
• Contain only one type of atom
• Cannot be broken down into simpler substance by any physical or chemical means
• Can exist as atoms or molecules
Sodium (Na)
• Contain atoms or 2 or more different elements
• Bonded together in a specific pattern
• Can be broken down by chemical means but not physical means
• Has different properties than its components
Sodium Chloride
(NaCl)
• Contains 2 or more substances (elements or compounds) that are NOT bonded together
• Can be separated physically
• Retains many of the same properties of its components
Salt Water (NaCl + H2O)
• The outer most electrons that are used
in bonding
• Determine the reactivity of an atom
– Reactivity = how likely an atom is to bond
with another atom
– Can use periodic table to determine
reactivity
• Strongest of chemical bonds
• Formed by the attraction between two oppositely charged ions – Ion = atom that has lost or gained an election
causing it to have a charge
• Valence electrons are stolen or taken
• Strong bond
• Sharing of electrons between atoms – Makes the outer shell of electron cloud
“feel” full
• A very weak bond
• Between molecules – not atoms!
• Between partial negative region of one molecule and a positive region of another
• WATER!!!
since we’re talking about hydrogen bonds….
…
• Nearly 70% of your body is made of water
• Water is where most cellular events take place
• Water helps move nutrients and other substances into and out of your cells
So…. It’s kind of important!
• Heat – Stores heat efficiently
– Heats more slowly and stores heat longer than most substances
– This allows our bodies to maintain a constant state
• Water bonds to itself and other substances
• Cohesion
– Hydrogen bonds between water molecules cause an attraction to each other
– Allows water to form drops and thin films
– Also causes surface tension – prevents water surface from stretching or breaking easily
• Adhesion
– Water molecules are also attracted to
other substances
• Universal solvent – Many substances dissolve in water making
solutions because of polarity • Solution = a mixture in which one or more
substances are evenly distributed in another substance
– Non-polar molecules DO NOT dissolve in water • EX: oil and water
• When solutions are made with water
as a solvent it may add or reduce
hydrogen ions
• This determines the acidity or alkalinity
of a solution
• Acids
– Compounds that form hydrogen ions
when dissolved in water
• Bases
– Compounds that reduce the
concentration of hydrogen ions when
dissolved in water
Measures the acidity or alkalinity of a substance
sounds scary but… it’s not!
• A process that involves the rearrangement of the molecular or ionic structure of a substance
• Six different types – Combustion
– Neutralization
– Synthesis – Decomposition
– Single displacement
– Double displacement
• During chemical reactions, energy is
both absorbed and released.
– Some absorb more than they release and
others release more than they absorb
• Some energy must be absorbed to
start a chemical reaction = activation
energy
• Endothermic: a chemical reaction that
absorbs more energy than it releases
• Exothermic: a chemical reaction that
releases more energy than it absorbs
Carefully rinse and dry off the thermometer
Carefully dump out the contents in the test tube down the sink. Rinse out all materials. Carefully and to your best ability dry it.
Rinse your test tube rack off. Place the clean test tube back.
Carefully remove the beaker from the hot plate. Dump the water into the sink.
Rinse the beaker and dry it off. Place it back on the hot plate when you’re done.
Rinse your graduated cylinder and dry them out to the best of your ability.
• Occurs when a compound containing
carbon and hydrogen reacts with
oxygen
• Creates water vapor, carbon dioxide,
and heat
CH4 2 O2 CO2 2 H2O
methane oxygen carbon dioxide water
• Happens when an acid and a base
are added to each other
• Complete neutralization occurs if the
same amount of hydrogen and
hydroxide ions are present and salt
and water are formed
HCl NaOH NaCl H2O hydrogen chloride sodium hydroxide sodium chloride water
• Occurs when simple compounds
combine to make a more complex
compound
2 Na Cl2 2 NaCl
• Occurs when a compound or
molecule breaks down into simpler
ones
2 H2O2 2 H2O O2
• Occurs when a pure element switches
places with an element in a
compound
Mg 2 HCl H2 MgCl2
• Occurs when the cations of two
compounds switch to form new
compounds
HCl AgNO2 AgCl HNO2
• Color change
• Gas production
• Light emission
• Odor
• Precipitates
• Temperature change
• Symbolic representation of a chemical
reaction
• Uses symbols and chemical formulas
– Chemical formulas represent a molecule
using the element symbols and numbers
• EX: CO2
A chemical equation has three sections
– Reactants
– Products
– Yield
( ) ( ) The stuff that goes into
the reaction
The stuff that comes out
of the reaction
YIELD
6 CO2 + 6 H2O C6H12O6 + 6 O2
• Subscript
– shows the number of atoms for that
element
• Coefficient
– Shows the number of molecules
6 CO2 + 6 H2O C6H12O6 + 6 O2
1. Identify and count the number of each element in the equation
2. The goal is to have an equal number of atoms for each element on both sides
- We use multiplication
Let’s give it a try…
This one is easy!
6 CO2 + 6 H2O C6H12O6 + 6 O2
reactants products
Let’s try another one
Na2 + F2 NaF2
reactants products
Balancing Chemical Equations
Worksheet
• Law of Conservation of Mass
– Mass cannot be created or destroyed
• Law of Conservation of Matter
– Matter cannot be created or destroyed
but it can change forms