Q. Which of the following molecules/ ions does not contain unpaired electrons?
A) $O_{2}^{2 -}$
B) $B_{2}$
C) $N_{2}^{+}$
D) $O_{2}$
Explanation
(a)
$O_{2}^{2 -}$ (Total number of electrons =18)
$\sigma 1s^{2},\ _{\sigma}^{*}1s^{2}\ ,\sigma 2s^{2},\ _{\sigma}^{*}2s^{2}\ ,\ \sigma 2p_{z}^{2},\pi 2p_{x}^{2} = \pi 2p_{y}^{2}\ _{\pi}^{*}2p_{x}^{2} = \ _{\pi}^{*}2p_{y}^{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.