MolSynapsequestion bank

MolSynapse / Question bank / Periodic Table and Periodicity / Ionisation enthalpy

NEET levelSingle correct optionDifficulty 1 of 3pt116

The first ionisation enthalpy of nitrogen is greater than that of oxygen because

Anitrogen has a lower nuclear charge, hence less repulsion
Bnitrogen has a stable half-filled $2 p^{3}$ configuration, whereas oxygen loses a paired $2 p$ electron
Cnitrogen has a larger atomic radius
Doxygen has a completely filled $2 p$ subshell

Answer: B

N

is

2 s^{2} 2 p^{3}

(half-filled, extra stable). Oxygen is

2 p^{4}

; removing one of the paired electrons relieves inter-electronic repulsion and gives the stable

2 p^{3}

ion. Thus 1402 for N exceeds

1314 kJ mo l^{- 1}

for O.

Practice Periodic Table and Periodicity More on Ionisation enthalpy

Previous questionNext question

More questions on Ionisation enthalpy