1. Chemistry of Life
All living and non-living things are made up of elements
Elements are substances that cannot be broken into anything more simple
Elements are made of atoms
Atoms are the smallest particle of an element that still have the characteristics of that element

2. Chemistry of Life Atoms are made of three subatomic particles Protons
Positive charge p+
Electrons
Negative charge e-
Neutrons
No charge n0

3. Chemistry of Life
Protons and Neutrons are located in the nucleus of an atom
What charge does the nucleus have?
Electrons are located in the regions that surround the nucleus (electron cloud)
The number of protons always equals the number of electrons so atoms have no overall charge

4. The Chemistry of Life Reading the periodic table
Chemical symbol: 1 or 2 letters that represent that element
Atomic Number: Indicates the number of protons and electrons in a normal atom that element
Atomic Weight: number with a decimal in most squares, total mass of all the subatomic particles in one atom of that element

5. Chemistry of Life

6. Compounds and Bonds Compound
Substance that is composed of atoms of two or more different elements that are chemically combined.
Atoms combine to become more stable
Atoms are most stable when their outermost energy level is full with 8 electrons
Examples: H20, CO2, NaCl

7. Compounds and Bonds Elements bond together to form compounds
Covalent Bonds
Atoms share electrons to become more stable
Example: water
Ionic Bonds
When atoms combine because they gained or lost an electron to become more stable
Example: sodium chloride (salt)

8. Chemical Reactions
Bonds between atoms are formed or broken causing new substances to be produced
Energy changes accompany chemical changes
Observable energy changes
Heat used or given off
Light
Metabolism is all of the chemical reactions within an organism

9. Writing Chemical Formulas
2C12H22O11
The subscript number in a formula indicate the number of atoms of each element in molecule of the substance.
The number in front of the chemical formula tells us the number of molecules of each substance.

10. Compounds vs Mixtures Compounds Mixtures
Two or more elements combined in a fixed ratio
Examples
CO2
H2O
CH4
C6H12O6
Mixtures
Combination of substances in any proportion
NOT chemically bound
Each substance keeps its own properties
Examples
Trail Mix
Kool Aid
Salt and Sand mixture

11. Solutions
A mixture of two or more substances where both are evenly distributed
Examples
Salt water
Sweet tea
Water vapor in the air

12. Acids and Bases pH is a measure of how acidic or basic a solution is
A scale of 0-14 is used to measure pH
Acids form H+ ions and have a pH below 7
Bases form OH- ions and have a pH above 7
Neutral solutions have a pH of 7