RE-NEET 2026 Chemistry Molecular Orbitals MCQ Question

The principle of molecular orbital theory states that electrons fill molecular orbitals in order of increasing energy. For Ne₂, the molecular orbital configuration is $(\sigma_{1s})^2 (\sigma^*_{1s})^2 (\sigma_{2s})^2 (\sigma^*_{2s})^2 (\sigma_{2p})^2$. The highest occupied molecular orbital (HOMO) is thus $\sigma_{2p}$, which is the last filled orbital.

Option C, $\sigma^*_{2p}$, is incorrect because it is an unoccupied antibonding orbital. Options A and B also do not represent the highest occupied state, as they refer to orbitals that are either lower in energy or unoccupied.