1. Polyatomic Ions OH Na + -

2. - Polyatomic ions A group of atoms covalently bonded together (molecule) with an overall charge (in other words, has gained or lost electrons so as a whole it is an ion) Ammonium NH 4 + Hydroxide OH - +

3. Polyatomic ions Act as a unit Act as a unit Endings typically –ate or –ite Endings typically –ate or –ite Parenthesis used in formula if more than one polyatomic ion in a compound Parenthesis used in formula if more than one polyatomic ion in a compound

4. Counting Atoms/Molecules Please identify how many atoms/molecules in the following: Ca(NO 3 ) 2 ____ Ca_____ NO 3 (NH 4 ) 3 PO 4 ____ NH 4 _____ PO 4 Na 2 CO 3 ____ Na_____ CO 3

5. Differentiated Activity Group 1: Bohr models Group 1: Bohr models Group 2: Finish powerpoint Group 2: Finish powerpoint

6. Example Find BIP and formula for sodium phosphate Sodium phosphate Na + & PO 4 3- IP = Na + & PO 4 3- IP = Na + & PO 4 3- Formula = Na 3 (PO 4 ) 1 = Na 3 PO 4 = Na 3 PO 4 B 3 1

7. Find the BIP and formula 1.) Barium phosphite 2.) Calcium nitrate 3.) Rubidium chlorate 1.) IP = Ba 2+ & PO 3 3- Formula = Ba 3 (PO 3 ) 2 Formula = Ba 3 (PO 3 ) 2 2.) IP = Ca 2+ & NO 3 - Formula = Ca(NO 3 ) 2 Formula = Ca(NO 3 ) 2 3.) IP = Rb + & ClO 3 - Formula = RbClO 3 Formula = RbClO 3 3 2B B 1 2 B 1 1

8. Naming - Example What is the name of the following compound: Al( ) 3 Aluminum nitrate NO 3

9. Name NaOH NaOH NH 4 CN NH 4 CN Ba(MnO 4 ) 2 Ba(MnO 4 ) 2 Sodium hydroxide Ammonium cyanide Barium permanganate

10. Reflection Write some simple things that will help you to remember how to write names and formulas for compounds with polyatomic ions Write some simple things that will help you to remember how to write names and formulas for compounds with polyatomic ions

11. Bond with a classmate Mg 2+ OH - BIP: _______ Mg 2+ & ________ OH - Formula: Mg(OH) 2 1 2