# What do we call the process when oxygen gas reacts with a SINGLE electron?

${O}_{2} \left(g\right) + {e}^{-} \rightarrow {O}_{2}^{-}$
Dioxygen has gained or accepted an electron; therefore, by definition it has been REDUCED. If you draw out the Lewis structure of this ${O}_{2}^{-}$ species, one of the oxygen atoms is a neutral radical, and the other is formally anionic.