Question

Ionization enthalpy of nitrogen is more than oxygen because of:

• A. extra stability of half filled orbitals
• B. more number of energy levels
• C. less number of valence electrons
• D. smaller size.

Answer 1

The correct option is A extra stability of half filled orbitals

The electronic configurations of $N$ and $O$ are $1s^{2}2s^{2}2p^3$ and $1s^{2}2s^{2}2p^4$ respectively. Nitrogen has a stable half-filled $2p$ orbital. It requires more energy to remove an electron from such stable configuration.