F2 (total electrons =18 ) σ1s2,σ*1s2,σ2s2,σ*2s2,σ2pz2 π2px2=π2py2,π*2px2=π*2py2 For N2, the valence orbital is bonding molecular, orbital and for F2, it is antibonding molecular orbital. So, bond order decrease by 0.5 in the former and increase by 0.5 in the latter.