1. Chemistry
Polyatomic Compounds

2. Polyatomic Compounds You do not need to memorize these!!!!
Groups of atoms that can be found as parts of a molecule.
These atoms bond in such a way that they have a net electric charge (usually negative)
Here are some of the most common polyatomics.
The resulting group of
atoms is an ion. So, it
can form an ionic bond (usually with a metal)
You do not need to memorize these!!!!

3. Polyatomic Compounds
We will not be drawing the structures for these atoms at this time.
However, we do need to be able to name them.
Write the name of the metal
(including the roman numeral if necessary)
Write the name of the polyatomic
Note: For a polyatomic, you do not need to change the ending of the molecule to ide.
Name the following
Ca3(PO4)2
Calcium Phosphate
CuSO4
Copper (II) Sulphate
BeCO3
Beryllium Carbonate

4. Polyatomic Exception There is only one really common positive
polyatomic ion,
This polyatomic will form ionic compounds with non metals.
To name these compounds,
Write the name of the polyatomic,
Write the name of the non metal changing the end to - ide
NH4+  Ammonium
NH4Cl
Ammonium Chloride
(NH4)2O
Ammonium Oxide

5. Multivalent/Polyatomic Chemical Formula
Give the chemical formula for the following compounds
Manganese (II) Sulphide
Tin (IV) Fluoride
Copper (II) Phosphate
Ammonium Sulphate
MnS
SnF4
Cu3(PO4)2
(NH4)2SO4

6. Try: Copper (II) Nitrate
e.g. 1/ What is the chemical formula of sodium phosphate?
Step 1 – Write the symbols of each ion, beginning with the cation (metal)
Na PO4
Step 2 – Write the ionic charge above each
Step 3 – Cross the charge to the oppose ions subscript
Step 4 – Re-write the formula. Make sure you put brackets around the polyatomic ion if it has gained a new subscript!
= Na3PO4
Try: Copper (II) Nitrate