what type of ions have names ending in -ide ?
They don’t all end in two. For example, you can have carbon dioxide (CO2) but you could also have carbon monoxIDE (CO). There is one basic rule, other than that you just have to memorize:
-Must be anions.
Negative ions that consist of a single atom are named by adding the suffix -ide to the stem of the name of the element.
Here are some examples of -IDEs: