O2+(15) =KKσ2s2σ2s2σ2pz2π2px2=π2py2π*2px1=π2py0 Bond order =
1
2
(8−3)=
5
2
=2.5 O2(16)=KKσ2s2σt2s2σ2pz2π2px2=π2py2π*2px1=π*2py1 Bond order =
1
2
(8−4)=2 O2−(17)=KKσ2s2σ*2s2σ2pz2π2px2=π2py2π*2px2=π*2py1 Bond order =
1
2
(8−5)=1.5 O22(18)=KKσ2s2σ*2s2σ2pz2π2px2=π2py2π*2px2=π*2py2 Bond order =
1
2
(8−6)=1 Note: As we know that as the bond order decreases, stability also decreases and hence the bond strength also decreases. Therefore the correct order of their increasing bond strength is O22<O2−<O2<O2+