O2 : σ 1s2 , σ* 1s2 , σ2s2 , σ* 2s2 , σ 2pz2 , π2px2,π2py2 , π∗2px1,π∗2py1 Bond order = 210−6 = 2 (two unpaired electrons in antibonding molecularorbital) O2+ : σ1s2 , σ*1s2 , σ2s2 , σ*2s2 , σ2pz2 , π2px62,π2py2 , π∗2px1,π∗2py0 Bond order = 210−5 = 2.5 (One unpaired electron in antibonding molecularorbital) Hence O2 as well as O2+ both are paramagnetic, and bond order of O2+ is greater than that of O2