Chem – ATE Versus ITE

What does ATE Versus ITE mean on the end of Polyatomic Ion Names?

 VIDEO Explanation of ATE Versus ITE on Polyatomic Ion Names

In Group 1 and 2 of the polyatomic ions list we can notice that many of the polyatomic ions have a name ending in -ATE or -ITE. The -ATE or -ITE is telling the reader each ion has certain a number of oxygens. To be clear, it does not exactly tell you how many oxygens, but it gives you an idea about them. Its purpose is to give you a consistent comparison between -ATE and -ITE.


Examples: A difference of one oxygen between them.

Carbonate has three oxygens

Carbonite has two oxygens


The hard rule here is -ate always has one more oxygen than -ite. Look at how each -ate and -ite are organized so that you could compare easily. However, -ate DOES NOT always mean it has three oxygens and the ending -ite does not always mean it has two oxygens.


PRACTICE PROBLEMS: Without looking at the polyatomic ions list try to write in how many oxygens each ion has by comparing it to its neighbor above or below. The first problem is done for you as an example.

Name Amount of Oxygen
Sulfate 4 oxygens
Sulfite 3 oxygens
Chlorate 3 oxygens
Chlorite 2 oxygens
Nitrite 2 oxygens
Nitrate 3 oxygens
Phosphite 3 oxygens
Phosphate 4 oxygens
Carbonite 2 oxygens
Carbonate 3 oxygens
Bromate 3 oxygens
Bromite 2 oxygens


Leave a Reply

You must be logged in to post a comment.