Ionic Bonding Part 2-Polyatomics Polyatomic ions are ______of elements (poly = many) that are covalently bonded together and have an overall ______charge.

When forming a compound, polyatomic ions work as a ______. So after criss-crossing the charges, it will be necessary to use parentheses if the subscript is bigger than ______.

Examples: Lithium and Arsenate + -3 Li and AsO4 Li3AsO4

Beryllium and Arsenate +2 -3 Be and AsO4 Be3(AsO4)2

When naming ionic compounds with polyatomic ions, the polyatomic ion already has a special name that ______changes.

Examples: LiC2H3O2 = lithium ______NH4OH = ______hydroxide

If the ending is a normal nonmetal, still change the ending to “ide”!

Exercise 4:

In the following grids:

1) Criss-cross the metal or ammonium and polyatomic ion in the appropriate. Use parentheses on the polyatomic ions when necessary. 2) Reduce if possible!

- -2 - - - C2H3O2 CO3 ClO3 OH NO3

Li+ (1) (2)

Mg+2 (3) (4)

+3 Ga (5) (6)

+ Rb (7) (8)

In+3 (9) (10)

NH + 4 (11) (12)

Naming Ionic Compounds with Polyatomic Ions Determining the name of an ionic compound with a polyatomic ion is even easier as the name of the polyatomic ion NEVER changes.

Examples: LiC2H3O2 = lithium acetate NH4OH = ammonium hydroxide Notice that the subscripts still have no effect on the name of the ionic compounds. Exercise 5: For each of the compounds made in the grids in exercise 4, write the name of the compounds.

1. ______2. ______

3. ______4. ______

5. ______6. ______

7. ______8. ______

9. ______10. ______

11. ______12. ______

Writing Ionic Compound Formulas from their Names

When given the name of the ionic compound that includes a polyatomic ion, the same basic steps for naming a binary ionic compound apply:

1) Write the symbols for the metal or ammonium and the polyatomic ion. 2) Figure out the charge on each. 3) Criss-cross the charges and reduce. Don’t forget to use parentheses if necessary.

Exercise 6: For each of the following named ionic compounds, write the correct formula. Be sure to follow all the steps presented above.

1. Lithium Arsenate ______2. Beryllium Arsenite ______3. Sodium Bicarbonate ______4. Magnesium Bisulfate ______5. Aluminum Bisulfite ______6. Potassium Borate ______7. Calcium Chlorite ______8. Gallium Chromate ______9. Rubidium Cyanate ______10. Strontium Cyanide ______11. Indium Dichromate ______12. Cesium Ferricyanide ______13. Barium Ferrocyanide ______14. Thallium Hypochlorite ______15. Ammonium Oxalate ______16. Ammonium Perchlorate ______17. Lithium Peroxide ______18. Beryllium Silicate ______19. Sodium Sulfite ______20. Magnesium Thiosulfate ______21. Aluminum Arsenate ______22. Potassium Bisulfate ______23. Calcium Bisulfite ______24. Gallium Borate ______