According to Molecular Orbital Theory, which of the following species has the highest bond order and is diamagnetic?

Solution

1. The electronic configuration of ${\text{N}}_2$ is $(\sigma 1\text{s}{)}^2({\sigma }^{\ast }1\text{s}{)}^2(\sigma 2\text{s}{)}^2({\sigma }^{\ast }2\text{s}{)}^2(\pi 2{\text{p}}_x{)}^2(\pi 2{\text{p}}_y{)}^2(\sigma 2{\text{p}}_z{)}^2$.
2. The bond order is calculated as $(10-4)/2=3$.
3. All electrons are paired, so ${\text{N}}_2$ is diamagnetic.
4. Hence the answer is (B).