Question

An anion is an atom that has

Answer 1

Negative charge? Gained electrons? Something else? You should be more specific.

Answer 2

A Negative Charge By Gaining one or more electron than its atomic no(Proton number)

Answer 3

@alanevans99 No, cations have a positive charge. http://chemistry.about.com/od/chemistryterminology/a/What-Is-The-Difference-Between-A-Cation-And-An-Anion.htm