1. Ions + Ionic Bonding Chapter 15

2. Bonds in Proportion

3. Valence electrons Valence e - the number of e - in the highest energy level Valence e - the number of e - in the highest energy level How do you determine valence e - ?

4. Quiz yourself How many valence e - for How many valence e - for Li, Na, K, Rb, Cs Li, Na, K, Rb, Cs Al Al Si Si P S Cl Cl

5. Octet Rule Atoms want a complete (full) outer energy level Atoms want a complete (full) outer energy level For most that means 8 electrons For most that means 8 electrons Exceptions to the rule? Exceptions to the rule? H, He, Li, Be, B – they want 2 H, He, Li, Be, B – they want 2 Elements will mimic the electron configuration of a noble gas Elements will mimic the electron configuration of a noble gas

6. Ions An ion is an atom An ion is an atom with a charge Cation is a positive ion (loses e-) Cation is a positive ion (loses e-) Anion is a negative ion (gains electrons) Anion is a negative ion (gains electrons) The common charge of an atom is called its OXIDATION Number

7. Oxidation Numbers What is the oxidation number of Na? What is the oxidation number of Na? +1 +1 What is the oxidation number of F What is the oxidation number of F -1 -1 What is the oxidation number for Mg What is the oxidation number for Mg +2 +2 What is the oxidation number for Te What is the oxidation number for Te -2 -2

8. Electrostatic Attraction A reactive element gains or loses e- in the presence of another element that will do the opposite A reactive element gains or loses e- in the presence of another element that will do the opposite (OPPOSITES ATTRACT) (OPPOSITES ATTRACT)

9. Ionic Bonds How and why does sodium bond with chlorine? 1e- 1e- http://www.youtube.com/watch?v=WEUXVQ95Rvk&feature=related&safety_mode=true&persist_safety_mode=1

11. More than just diatomics Can you figure these out? Mg + F Mg 2+ + F - MgF 2 Al + Cl Al +3 + Cl - AlCl 3

12. Swap and Drop Write the oxidation number Write the oxidation number Swap the positive and negative ox # and make it the subscript of the other element Swap the positive and negative ox # and make it the subscript of the other element Ex: Mg 2+ + Cl -1 → MgCl 2

13. Try these K + O K 2 O K 2 O Al + O Al 2 O 3 Al 2 O 3 Mg + N Mg 3 N 2 Mg 3 N 2

14. Polyatomic Ions You should know these names of polyatomic ions NO 3 - nitrate OH - hydroxide ClO 3 - chlorate SO 4 2- sulfate PO 4 3- phosphate

15. Try These Mg 2+ + NO 3 - Mg(NO 3 ) 2 Mg(NO 3 ) 2 K + + OH - KOH KOH Ca 2+ + PO 4 3- Ca 3 (PO 4 ) 2 Ca 3 (PO 4 ) 2