a
\({O}_{2}^{-}=\left(\sigma_{1 {~s}}\right)^{2}\left(\sigma_{1 {~s}}^{*}\right)^{2}\left(\sigma_{2 {~s}}\right)^{2}\left(\sigma_{2 {~s}}^{*}\right)^{2}\left(\sigma_{2 {p}_{{z}}}\right)^{2}\)

\(\left(\pi_{2 {p}_{{x}}}^{2}=\pi_{2 {p}_{{y}}}^{2}\right)\left(\pi_{2 {p}_{{x}}}^{*_{2}}=\pi_{2 {p}_{{y}}}^{*_{1}}\right)\)

\(\text { Bond order }=\frac{10-7}{2}=1.5\)

and paramagnetic