Verified Solution • 2025–26 Session moderate

QJEEM21Chb987: JEE Main 2021 Chemistry - Class 11 JEEM21Chb987 Solution: Match List - I with List - II. List I Electronic configuration…

Match List - I with List - II.

	List I Electronic configuration		List II ${\Delta _i}H$ in kJ $mo{l^{ - 1}}$
(a)	$1{s^2}2{s^2}$	(i)	801
(b)	$1{s^2}2{s^2}2{p^4}$	(ii)	899
(c)	$1{s^2}2{s^2}2{p^3}$	(iii)	1314
(d)	$1{s^2}2{s^2}2{p^1}$	(iv)	1402

Choose the most appropriate answer from the options given below :

Multiple Choice Options

A (a) $\to$ (i), (b) $\to$ (iii), (c) $\to$ (iv), (d) $\to$ (iii)
B (a) $\to$ (iv), (b) $\to$ (i), (c) $\to$ (ii), (d) $\to$ (iii)
C (a) $\to$ (ii), (b) $\to$ (iii), (c) $\to$ (iv), (d) $\to$ (i)
D (a) $\to$ (i), (b) $\to$ (iv), (c) $\to$ (iii), (d) $\to$ (ii)

Step-by-Step Verified Solution

(a) 1s² 2s²

\to

Be

(b) 1s² 2s² 2p⁴

\to

O

(c) 1s² 2s² 2p3

\to

N

(d) 1s² 2s² 2p¹

\to

B

The ionization enthalpy order is

B < Be < O < N

Be has more IE compared to B due to extra stability & N has more IE compared to oxygen due to extra stability.

Hence, N

\to

1402 kJ/mol

O

\to

1314 kJ/mol

B

\to

801 kJ/mol

Be

\to

899 kJ/mol

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