Assertion :First ionization energy is lower than oxygen.
Reason :Across a period effective charge decreases.

Assertion :First ionization energy of N2 is lower than oxygen. Reason :Across a period effective charge decreases.

Assertion : First ionization energy of nitrogen is lower than oxygen Reason : Across the period effective nuclear charge decreases

Assertion (A): IE_(1) of N is lower than O . Reason (R ) : Across a period Z_(eff) decrease.

Assertion (A): IE_(1) of N is lower than O . Reason (R ) : Across a period Z_(eff) decrease.

The ionization energy of N is more than that of oxygen because:

Assertion (A) : The first ionization energy of Al is lower than Mg. Reason (R ) : Atomic radius of Al is smaller than Mg.

The first ionization enthalpy of O is lower than that of N.