Find the bond order in O2 molecule.

O atom=1s2 2s2 2p4∴ Total number of electrons in O2 molecule                  =2×8=16These 16 electrons occupy different molecular orbitals(M.0.) in the increasing order of their energies. Thus Electron configuration of O2 molecule=KKσ2s2σ2s∗2σ2pz2π2px2=π2py2 π*2px1=π*2py1 ∴  Bond order = no. of election   - no. of electrons in    in bonding M.O      antibonding M.O.2                  =8−42=2   Ans.