Bond order of O22− : Electronic : σ1 s2σ⋆(s2σ2 s2σ∗2 s2σ2Pz2(π2Px2=π2Py2) (π2Px2=π2⋆Py2)σ⋆2pz∘ Bond order =2 Bonding − Antibonding electrons =210−8=1 Bond order of B2 : σ1s2σ1s22σ2s2σ⋆2s2σ2pz2 Bond order =26−4=1 ∴O22− and B2 has same bond order 1.