1. Polyatomic Ions Thursday, October 12, 2017
Objective: I will learn different polyatomic ions, and how they form compounds
Entry Task -
Chem Catalyst 22

2. Definition
Polyatomic ions - An ion composed of a group of atoms with an overall positive or negative charge. Most polyatomic ions are anions (one exception is NH4+, a cation).
poly - many
atomic - atoms

3. 2 Games Play Ionic Grid with your lab group - 20 minutes
Return cards to teacher
Get one new card
Play “3-minute Bonding”
You may need more than 2 people to form a real compound
Each person in the group writes the cation, anion, chemical formula, and point value down (1 pt/card in compound). Leave chemical name for later
As soon as all group members record the compound, break apart and find new compound
When you hear “SWITCH”, trade cards with someone

4. Definition
Polyatomic ions - An ion composed of a group of atoms with an overall positive or negative charge. Most polyatomic ions are anions (one exception is NH4+, a cation).
poly - many
atomic - atoms
How can you tell if an ionic compound contains a polyatomic ion?
What naming patterns did you notice during the game?

5. Polyatomic Naming Patterns
Ions that differ only by number of oxygen atoms follow a pattern:
NO2- - nitrite
NO3- - nitrate
PO33- - phosphite
PO43- - phosphate
ClO4- - perchlorate
ClO3- - chlorate
ClO2- - chlorite
ClO- - hypochlorite
Stem comes from non-oxygen atom (nitrogen = nitr-, phosphorus = phosph-, chlorine = chlor-)
If two ions, higher # of oxygens ends in -ate, and lower ends in -ite
If 4 ions:
per-stem-ate
stem-ate
stem-ite
hypo-stem-ite

6. Exit Task What is the NAME of the compound Be(NO3)2?
What ions are present in this compound and what are the charges on the ions?