Question

Which of the following molecules/ions does not contain unpaired electrons ?

• A. $O_{2}^{2-}$
• B. $B_{2}$
• C. $N_{2}^{+}$
• D. $O_{2}$

Answer 1

The Correct Option is A

$O_{2}^{2-}$ (Total number of electrons = 18) $\sigma 1s^{2}, \sigma^{* } 1s^{2}, \sigma2s^{2}, \sigma^{* } 2s^{2},\sigma2p_{x}^{2}, \pi 2p_{x}^{2}$ $=\pi 2p_{y}^{2} \pi^{ *} 2p_{x}^{2}=\pi^{* } 2p_{y}^{2}$