1. Warm Up What is the charge of a cation? negative or positive How are cations formed? What is the charge of an anion? negative or positive How are anions formed?

2. State the number of electrons gained or lost in forming the following ions: Mg 2+ Rb 1+ Br - Al 3+

3. State the number of electrons gained or lost in forming the following ions: Mg 2+ Lost 2 electrons Rb 1+ Lost 1 electrons Br - Gained 1 electron Al 3+ Lost 3 electrons

4. Write the formula unit (element symbol and charge) for the following ions: Sodium ion Bromide Sulfide Barium ion

5. Write the formula unit (element symbol and charge) for the following ions: Sodium ionNa + BromideBr - SulfideS 2- Barium ionBa 2+

6. Writing Chemical Formulas 6.4 Writing Chemical Formulas

7. Binary Ionic compounds (2 elements) Chemical Formula Rule: 1.Identify ion symbols and charges 2.Write cation symbol 1 st followed by the anion symbol 3. Balance charge (“cross multiplication”) Example: Write the formula for sodium chloride. Na + and Cl - NaCl

8. Na + O 2- Formula: Na 2 O Na + Na + O 2- *** You do not need to write a 1, if the subscript is not present you assume it is one!!

9. Trick for balancing “cross multiply” Ca 2+ Cl - Ca Cl 2 Ca 2+ Cl - Cl -

10. Naming the ionic compound when given a formula 1.Cation full name followed by the anion(-ide ending)

11. Naming: Cation + anion-ide Example: CaCl 2 Calcium chloride NaClSodium Chloride When looking at the name, is the number of atoms indicated? How are you supposed to figure out the number of atoms???

12. You try it! Li + S 2- Write the formula and name!

13. You try it! Li + S 2- Write the formula and name! Li 2 S Lithium Sulfide

14. The ions of calcium and sulfur form a binary ionic compound. Write the formula and name of this resulting compound:

15. Calcium ion and Sulfide Write the formula and name of this resulting compound: CaS Calcium sulfide

16. You try it! Write the ions, chemical formula and chemical name of the ionic compound formed when potassium and oxygen ions interact. Ions: Chemical Formula: Chemical name:

17. Write the ions, chemical formula and chemical name of the ionic compound formed when potassium and oxygen ions interact. Ions: K + O 2- Chemical Formula: K 2 O Chemical Name: Potassium oxide

18. Ternary Compounds one ion is monatomic other is a polyatomic ion……. Example: Lead Nitrate Pb 2+ and ( NO 3 - ) Formula: Pb (NO 3 ) 2

19. You try it! Sodium hydrogen phosphate Na 1+ HPO 4 2- Write the formula:

20. Sodium hydrogen phosphate Na 1+ HPO 4 2- Write the formula: Na 2 HPO 4

21. 6.3 and 6.4 In Class Practice