Question

Which of the following has the highest bond order ?

• A. $N_2$
• B. $O_2$
• C. $He_2$
• D. $H_2$

Answer 1

Answer: (A)

$N_2$

Answer 2

Molecular orbital configuration of

$N _{2}=14 e^{-}=\sigma 1 s^{2},{ }^{*} 1 s^{2}, \sigma 2 s^{2}, \sigma^{*} 2 s^{2},$
$\sigma 2 p_{x}^{2}, \pi 2 p_{y}{ }^{2}, \pi 2 p_{z}{ }^{2}$

Bond order $=\frac{N_{b}-N_{a}}{2}=\frac{10-4}{2}=3$

Similarly for $O _{2}$ molecule, bond order $=2$

For $He _{2}$ molecule, bond order $=0$

For $H _{2}$ molecule bond order $=1$ So, $N _{2}$ has highest bond order.