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.
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.
- (A)Both A and R are correct and R is the correct explanation of A.✓ Correct
- (B)Both A and R are correct but R is NOT the correct explanation of A.
- (C)A is correct but R is not correct.
- (D)A is not correct but R is correct
Answer: (A)
Solution
Assertion A is correct: nitrogen has higher first ionization energy than oxygen. Reason R is also correct and explains A: in oxygen's 2p subshell, four electrons occupy three orbitals, so two must pair in one orbital. This pairing increases electron-electron repulsion, making it easier to remove one electron from oxygen compared to nitrogen (where all three 2p electrons are unpaired).
JEE Main · 2022 · 29 Jun 2022 · Shift 2 · Single correct option