How doe an ion become negative?

Answer 1

The positivity and negativity of an ion is determined by the number of electrons compared to that of protons. If there are more electrons than protons in the ion, it is considered negative. It becomes negative by gaining electrons, which can happen a number of ways. Simply put, most often it gains electrons by pulling them off of other elements and molecules. The more electronegative an element is, the easier it is for it to do this. Elements are most stable in their "octet" configuration where all of the available spots in an orbital are filled. Elements with less than a perfect octet will rip electrons off of other things.