Question:
In the following the correct bond order sequence is:
Correct Option: , 3
Solution:
$\mathrm{O}_{2}$ (16 electrons)
$\sigma_{1 \mathrm{~s}}^{2}, \sigma_{1 \mathrm{~s}}^{* 2}, \sigma_{2 \mathrm{~s}}^{2}, \sigma_{2 \mathrm{~s}}^{* 2}, \sigma_{2 p_{\mathrm{z}}}^{2}$
$\pi_{2 p_{x}}^{2}=\pi_{2 p_{y}}^{2}, \pi_{2 p_{x}}^{*_{1}}=\pi_{2 p_{y}}^{*_{1}}, \sigma_{2 p_{z}}^{*}$
Bond order of $\mathrm{O}_{2} \Rightarrow 2$
Bond order of $\mathrm{O}_{2}^{-} \Rightarrow 1.5$
Bond order of $\mathrm{O}_{2}^{2-} \Rightarrow 1$
Bond order of $\mathrm{O}_{2}^{+} \Rightarrow 2.5$