1. Writing Compounds

2. First Some Terms Ions - elements that have lost or gained an electron and have a charge Cation- elements lose an electrons positive charge Anion - elements gain an electron negative charge

3. Charges equal zero Fe 3+ combines with O 2- LCM = 6 Fe 2 O 3

4. Practice Problems Na + & O 2- Al 3+ & P 3- Mn 5+ & P 3- Sn 4+ & Cl - Pb 2+ & N 3- Answers Na 2 O AlP Mn 3 P 5 SnCl 4 Pb 3 N 2

5. Names from formulas Identify the Cation and Charge Identify the Anion and Charge Balance the Charges to equal zero

6. practice Barium phosphide Cation Ba 2+ Anion P 3- LCM 6 Ba 3 P 2

7. Barium chloride Strontium phosphide Calcium chloride Zinc arsenide Potasium sulfide Ytterium bromide BaCl 2 Sr 3 P 2 CaCl 2 Zn 3 As 2 K 2 S YBr 3