Question

According to molecular orbital theory, the number of unpaired electron(s) in $O _{2}^{2-}$ is:

Answer 1

Molecular orbital configuration of $O _{2}^{2-}$ is
$\sigma_{1 s }^{2} \sigma_{1 s }^{* 2} \sigma_{2 s }^{2} \sigma_{2 s }^{* 2}\left(\pi 2 p _{ x }^{2}=\pi 2 p _{ y }^{2}\right)\left(\pi_{2 px }^{* 2}=\pi_{2 py }^{* 2}\right)$
Zero unpaired electron