1. Bonding

2. Valence Electrons In the highest energy level Determine chemical properties. Elements bond to get 8 valence e- (octet rule)

3. Anions, Cations, and Electron Configuration Cations form by losing valance electrons to take on a noble gas configuration (ns 2 np 6 )

4. Anions, Cations, and Electron Configuration Cations form by losing valance electrons to take on a noble gas configuration (ns 2 np 6 ) So Li loses the 2s 1 electron to form Li +1. Mg loses both 3s 2 electrons to form Mg +2 Al loses three electrons from 3s 2 3p 1 to form Al +3

5. Anions, Cations, and Electron Configuration Anions form by gaining valance electrons to take on a noble gas configuration (ns 2 np 6 ) So F becomes F 1- by gaining a 2p electron to have the new valance configuration 2s 2 2p 6. S becomes S 2- by gaining two 2p electrons to have the new valance configuration 3s 2 3p 6. N becomes N 3- by gaining three 2p electrons to have the new valance configuration 2s 2 2p 6.

6. Ionic Compounds Made of metal cations (+) and nonmetal anions (-) Have no charge Solid at room temperature High melting points Conduct electric current when dissolved in water Na + Cl -

7. Writing Ionic Formulas 1.Write each ion with the correct charge (cations first!) 2.Bring the charge # (NOT the + or -) down as a subscript and switch which element it goes to Aluminum and oxygen Al 3+ O 2- Al 2 O 3

8. Naming Ionic Compounds Name of the cation –Roman numeral for cations with mutliple + charges Name the anion –ide is single anion –-ate or -ite is polyatomic CaF 2 Li 3 PO 4 PbS 2 Calcium fluoride Lithium phosphate Lead (IV) sufide

9. Covalent Bonds 1.Nonmetal atoms are held together by sharing electrons 2.low melting and boiling point 3.All phases at room temperature

10. Diatomic Molecules H 2, N 2, O 2, F 2, Cl 2, Br 2, I 2, At 2

11. Naming and Writing Formulas for Covalent Compounds Indicate # of each atom using prefixes (mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca) The first element does not use mono if there’s only one. NO 2 P 2 O 4 nitrogen dioxide diphosphorus tetroxide

12. Lewis Structures Step 1: Set up the following table to determine bond numbers AtomV- Electrons # Needed S O O O Total Step 2: Connect atoms based on bond numbers calculated Step 3: Fill octets with unshared electrons

13. VSEPR THEORY Valence Shell Electron Pair Repulsion. tetrahedaral Trig planar linear bent Trig pyramid