Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R .…

Given below are two statements. One is labelled as
Assertion A and the other is labelled as Reason R.
Assertion A : The first ionization enthalpy for oxygen is lower than that of nitrogen.

Reason R : The four electrons in 2p orbitals of oxygen experience more electron-electron repulsion.

In the light of the above statements, choose the correct answer from the options given below.

  1. Both A and R are correct and R is the correct explanation of A.
  2. Both A and R are correct but R is NOT the correct explanation of A.
  3. A is correct but R is not correct.
     
  4. A is not correct but R is correct

Solution

Ionization energy of oxygen is less than that of nitrogen because 2p subshell of nitrogen is half filled, and half filled orbitals have some extra stability, so removing electrons from them will be little more difficult.
And In oxygen atom, 2 of the four 2p electrons must occupy the same 2p orbital resulting in an increased electron electron-repulsion.

N=1s22s22p3

O=1s22s22p4

Asked in: JEE Main 2022 (29 Jun Shift 2)

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