Question

Why the electron ionization enthalpy of oxygen is less than that of nitrogen?

Answer 1

Answer:

Explanation:

Oxygen has low ionisation energy (than that of nitrogen). It is due to an electron being added to an already half full orbital in oxygen, which results in electron electron repulsion, which will lower the ionisation energy. ...

Answer 2

Answer:

(1) The electronic configuration of nitrogen (N, Z = 7) is 1s², 2s², 2p³ and that of oxygen (O, Z=8) is 1s², 2s² 2p^4.

(2) Nitrogen atom acquires extra stability due to half- filled 2p-orbitals while oxygen can acquire half-filled orbital and extra stability by losing one electron. Thus, oxygen can easily lose one electron.

(3) Nitrogen requires more energy to remove an electron due to extra stability. Therefore, first ionisation enthalpy of oxygen is less than that of nitrogen.