• # question_answer Can we have a diatomic molecule with its ground state molecular orbitals full with electrons? Give a reason for your answer.

No. Because bond order becomes zero, e.g., in case of $H{{e}_{2}},\,B{{e}_{2}},\,N{{e}_{2}},$ etc. Note that in ${{H}_{2}},\,{{\sigma }_{1s}}M.O.$is full but $\sigma _{1s}^{*}$is empty.