Basic chemistry

•Atoms to Organisms

Section 1 Vocabulary:9 words

1. atom ( Proton, neutron, electron),

2. element,

3. isotope,

4. compound,

5. covalent bond,

6. molecule,

7. ion,

8. ionic bond,

9. Vander Waals forces.

WHAT IS MATTER?

Anything that has

mass and volume!

ATOMS AND ELEMENTS

1. ATOMS: make up elements, they are the smallest part of an element that still has all of the properties of the element.

2. ELEMENT: a substance that can not be broken into simpler substances.

Model of an Atom

• Moving charged particles

• Protons +• Neutrons 0• Electrons –

• Most of the volume is empty space!

ELECTRONS ARE IMPORTANT!

• Electron spend their time in areas around the nucleus.

• Each area or orbital hold a certain number of electrons.

• The first orbital for electrons holds 2

• The next level holds 8

• The electrons are in pairs!!!

• They fill the open spaces one at a time

BONDING• This leaves one electron with out a partner

• This electron will be more stable with another

electron in the orbital with it. The atom is likely to

bond with an atom that has one extra electron.

ATOMIC NUMBERis

the number of protons in an atom

# protons

• ELECTRONS ARE LIGHT!

• PROTONS ARE HEAVY

• NEUTRONS ARE HEAVY

SO………

The mass of an atom is made up of the protons

and neutrons!

ATOMIC MASS• The number of protons plus the number of

neutrons in an atom. • How many neutrons?• Subtract the atomic number from the mass

number!

19 atomic number

Example: K symbol Potassium name 39.098 Atomic mass

19 atomic number= # P = # E

K symbol Potassium name

39.098 Atomic mass= P + N

Protons = 19 Electrons =19 Neutrons =20

# NEUTRONS

39

- 19

20 NEUTRONS

How many electrons?

• The number of electrons is equal to the number of protons unless the atom has a charge!

• 10 p+ = 10 e - neutral

• 10 p + 9 e - positive 1 charge +1

• 10 p + 11 e - negative 1 charge -1

3. isotopes

WHAT IS DIFFERENT ABOUT ISOTOPES?

THE NUMBER

OFNEUTRONS

OR ATOMIC MASS

4. COMPOUNDS

• A SUBSTANCE THAT CONTAINS 2 OR MORE ELEMENTS CHEMICALLY COMBINED.

5. Covalent Bonds

• Sharing of electrons to make both atoms have a complete set of orbitals

ME too!

I could use one more electron

I just need 2

more and I will be perfect!

6. molecule,

• When 2 or more atoms are combined with chemical bonds a molecule is formed.

7. ion,

• An atom that gains or loses an electron and therefore has a charge.

+ -

8. Ionic Bonds• ELECTRIC ATTRACTION!!!!!

+

-• NEGATIVE TO POSITIVE!

• IONS HAVE A CHARGE-

• AN EXTRA ELECTRON (-)

• MISSING ELECTRON (+)

Ionic- donation!!!

One spare.-1 charge

Needs one

+ 1 charge

Sodium chloride

• An example of an ionically bonded molecule

Let’s share!!!!!!!!

Now we all are happy!!!

• 9. Vander Waals forces. When molecules come close together and positive and negative regions are attracted the forces of those attractions are called van der Waals forces.

• Notes: the strength depends on the size and shape of the molecules. They are not as strong as covalent and ionic bonds.

• They are important to biological processes!

• Water is an example of a substance with van der Waals forces!

Water

Hydrogen bond

Surface Tension

• Water to Water bonds

cohesion• Water to water

• Adhesion: water to something else

meniscus

Capillary Action

• Water “pulls” itself up a tube by its adhesion to the sides of the tube

pH• A measure of hydrogen ion concentration

• Scale 1- 14

• 1-6 acid

• 7 neutral

• 8-14 base

pH paper

• Measure by a color change

pH activity

• Make a data chart of the items to be tested

• Test the pH and record the number

item pH