Polyatomic Ions

Common Polyatomic Ions

Polyatomic Ions are compounds composed of different elements. All polyatomic ions have a positive or negative charge. 

Polyatomic Ions with Halogens

Concept: The 4 Characteristics of Polyatomic Ions with Halogens


Concept: Naming System for Polyatomic Ions with Halogens


The naming system for polyatomic ions with halogens is based on the number of oxygens present. 

Polyatomic ions that contain only oyxgen and fluorine are imaginary and do not exist. However, in terms of naming we can still use the rules we learn to name these imaginary polyatomic ions. 

Example: Name each of the following compounds.

            a. BrO4 –                                                                                                          b.  FO2


            c. ClO –                                                                                     d.  IO3