• # question_answer Why super oxides of alkali metals are paramagnetic while normal oxides are diamagnetic?

Super oxides contain the ion $O_{2}^{-}$ which has the structure ${{(:\overset{.\,\,\,\,.}{\mathop{O}}\,\overset{.\,\,.\,\,\,.}{\mathop{-}}\,\overset{.\,\,\,.}{\mathop{O}}\,:)}^{-}}$ containing a three electron bond, i.e., it has one unpaired electron and hence is paramagnetic. Normal oxides containing the ion ${{[:\underset{\,\,\,.\,\,\,.}{\overset{.\,\,\,.}{\mathop{O}}}\,:]}^{2-}}$ do not have any unpaired electrons and hence are diamagnetic.