Question

most of the polyatomic ions are oxyanions. from the prefix and root word, what do you think \oxyanion\ means?

which oxyanions do you need to know?

the most common form of a polyatomic ion contains the suffix –ate. what are the most common polyatomic ions?

when a polyatomic ion contains one less oxygen than the most common form, it is given the suffix –ite. which polyatomic ions contain the suffix –ite?

when a polyatomic ion contains two oxygen atoms less than the most common form, it is given the prefix hypo- (hypo- means below). which polyatomic ion has the prefix hypo-?

when a polyatomic ion contains one oxygen atom more than the most common form, it is given the prefix per- (per- means completely or large amount). which polyatomic ion has per-?

Explanation:

The problem is about polyatomic ions and oxyanions, which falls under Chemistry (a subfield of Natural Science). To answer the first question about "oxyanion": The prefix "oxy-" relates to oxygen, and "anion" is a negatively charged ion. So combining these, "oxyanion" should mean a polyatomic anion that contains oxygen (since most polyatomic ions that are oxyanions have oxygen in their structure, like sulfate, nitrate, etc.). For example, the word parts: "oxy" (oxygen) + "anion" (negative ion) → an anion containing oxygen.

Answer:

An oxyanion is a polyatomic anion that contains oxygen (e.g., sulfate $\ce{SO_4^{2-}}$, nitrate $\ce{NO_3^-}$ are oxyanions as they are negative ions with oxygen in their structure).