Chemistry - Complete s-block Question with Solution | TestHub

The superoxide ion, ${\mathrm{O}}_2^{-}$, in ${\mathrm{KO}}_2$ has an unpaired electron in its ${\pi }^{\ast }$ antibonding molecular orbital. This unpaired electron allows ${\mathrm{KO}}_2$ to absorb certain wavelengths of light and reflect others, resulting in a distinct color (yellow-orange). The other compounds are simple oxides with no unpaired electrons.