1. Compounds

2. Definition of compound/ molecule: two or more elements bonded together in a definite ratio. Example: H20 (2 hydrogen and 1 oxygen)
Compound are much different than the elements that make them up. Example: Water is much different than H2 or O2 Compounds are held together by chemical bonds.

3. Chemical Bonds: A transfer or sharing of electrons between two or more atoms.
**All atoms seek to have the outer shell full. They will give, take or share in order to do this.

4. Ionic Bonds – The transfer of outer electrons

5. Polar vs. Nonpolar Covalent Bonds
Polar Bonding- unequal sharing of electrons
Nonpolar Bonding – equal sharing of electrons

6. 2. Covalent Bond- The sharing of outer electrons
Example: Oxygen
Before
After
Covalent Bonds are VERY STRONG!

7. Chemical Formulas The “recipe” for what is in the molecule
The symbol and number of each element present
Examples:
Water Hydrogen + 1 Oxygen
H20
b. Methane 1 Carbon + 4 Hydrogen
CH4

8. Tricky Example
Ca7
H2PO4
Fertilizer – Ca7(H2PO4)2 Calcium – 7 Hydrogen – 4 Phosphorous – 2 Oxygen - 8