Question:
If the magnetic moment of a dioxygen species is $1.73 \mathrm{~B} . \mathrm{M}$, it may be:
Correct Option: 1
Solution:
$\mu=\sqrt{n(n+2)}$ B.M.
$1.73=\sqrt{n(n+2)}$
$n=1$
$\mathrm{O}_{2}^{+}=\sigma 1 s^{2} \sigma^{*} 1 s^{2} \sigma 2 s^{2} \sigma^{*} 2 s^{2} \sigma 2 p_{z}^{2} \pi 2 p_{x}^{2}$
$=\pi 2 p_{y}^{2} \pi^{*} 2 p_{x}^{1}=\pi^{*} 2 p_{y}^{\circ}$
$\mathrm{O}_{2}^{-}=\sigma 1 s^{2} \sigma^{*} 1 s^{2} \sigma 2 s^{2} \sigma^{*} 2 s^{2} \sigma 2 p_{z}^{2} \pi 2 p_{x}^{2}$
$=\pi 2 p_{y}^{2} \pi^{*} 2 p_{x}^{2}=\pi^{*} 2 p_{y}^{1}$