O2−=σ1s2<σ∗1s2<σ2s2<σ∗2s2<σ2px2=π2py2=π2pz2<π∗2py2=π∗2pz1
Bond Order =26−3=1.5
O2=σ1s2<σ∗1s2<σ2s2<σ∗2s2<σ2px2<π2py2=π2pz2<π∗2py1=π∗2pz1
Bond order =26−2=2
N2=σ1s2<σ∗1s2<σ2s2<σ∗2s2<π2pz2=π2pz2<σ2px2
Bond order =26−0=3
According to MOT ; electronic configuration of N2+ is:
N2+=σ1s2<σ∗1s2<σ2s2<σ∗2s2<π2px2=π2py2<σ2pz1
Bond order =21(9−4)=2.5
i.e., 2π bonds and 0.5σ bonds.