What types of atoms usually become negative ions?

1 Answer
Sep 27, 2017

Usually, non-metals......

Explanation:

Non-metals come the right hand side of the Periodic Table, i.e. the right hand side of the Periodic Table as we face it.....(I will get sick of qualifying this one day!).

Because we add electrons to the same valence shell, and we also add protons to the nucleus, atoms in general undergo a contraction in atomic radius, with the smallest atoms to the right of the Periodic Table (again, as we face it, but I think you know what I mean).

And thus elements to the right side of the Periodic Table, fluorine, chlorine, oxygen, TEND to be oxidizing, i.e. they accept electron density as a consequence of their unshielded nuclear charge.

And thus nitrogen, oxygen, fluorine, chlorine, etc. TEND to form negative ions, i.e. #N^(3-)#, #O^(2-)#, #F^-#, and #Cl^-#; clearly the PARENT atoms (or molecules) are oxidizing species.

On t'other hand, metals tend to be reducing; they tend to donate electrons to an oxidant..... Capisce?