Chemistry - CHEMICAL BONDING Question with Solution | TestHub

According to MOT:

$$\begin{array}{rl}& {\mathrm{O}}_2{}^{-}:\sigma 1{\mathrm{s}}^2,\stackrel{\ast }{\sigma }1{\mathrm{s}}^2,\sigma 2{\mathrm{s}}^2,\stackrel{\ast }{\sigma }2{\mathrm{s}}^2,\sigma 2{\mathrm{p}}_{\mathrm{z}}^2,\pi 2{\mathrm{p}}_{\mathrm{x}}^2=\pi 2{\mathrm{p}}_{\mathrm{y}}^2,\stackrel{\ast }{\pi }2{\mathrm{p}}_{\mathrm{x}}^1=\stackrel{\ast }{\pi }2{\mathrm{p}}_{\mathrm{y}}^0\\ & {\mathrm{O}}_2{}^{-}:\text{Bond order }=\frac{1}{2}(10-7)=1.5(paramagnetic)\\ & {\mathrm{O}}_2:\text{ Bond order }=\frac{1}{2}(10-6)=2(paramagnetic)\end{array}$$