Question

Which of the following statements concerning molecular orbital theory is/are true?

1. Bonding orbitals are equal in energy to their corresponding anti-bonding orbitals.

2. Adding electrons to anti-bonding orbitals destabilizes molecules.

3. Unlike when we fill atomic orbitals, we DON'T use Hund's Rule to fill molecular orbitals.

Group of answer choices

Answer 1

Among the given options, option 2 Adding electrons to anti-bonding orbitals destabilizes molecules is correct. This is because anti-bonding molecular orbitals result from out-of-phase combinations of atomic orbital wave functions and hence electrons in these orbitals make a molecule less stable.

Option 1 is not true as anti-bonding orbitals will have higher energy than the bonding orbitals.

Option 3 is also not true as filling electrons in molecular orbitals will also follow Hund's rule according to which the sublevels in same orbitals are singly occupied first followed by double occupation.