During change of O2 to O2- ion, the electron adds on which one of the following orbitals?

During change of O2 to O2- the electronic configuration of O2 total e-=16 is σ1s2,σ*1s2,σ2s2,σ*2s2,σ2pz2π2px2≈π2pv2,π*2px1≈π*2pv1and configuration of O2-,totale-=17σ1s2,σ*1s2,σ2s2,σ*2s2,σ 2pz2,π2px2≈π2py2,π*2px2≈π*2py1Thus, electron goes in the π*-orbital.