Q8 / 75 · JEE Main 2026 (08 April Shift 2) · Chemistry
Match List-I with List-II.List-I
Electronic configuration of neutral atom (where $n=2$) List-II
$1^{st}$ Ionization Energy (kJ mol$^{-1}$) A. $ns^2$ I. $2080$ B. $ns^2np^1$ II. $899$ C. $ns^2np^3$ III. $800$ D. $ns^2np^6$ IV. $1402$
Choose the correct answer from the options given below:
| List-I Electronic configuration of neutral atom (where $n=2$) | List-II $1^{st}$ Ionization Energy (kJ mol$^{-1}$) |
|---|---|
| A. $ns^2$ | I. $2080$ |
| B. $ns^2np^1$ | II. $899$ |
| C. $ns^2np^3$ | III. $800$ |
| D. $ns^2np^6$ | IV. $1402$ |
- Correct answerAA-II, B-III, C-IV, D-I
- BA-IV, B-III, C-II, D-I
- CA-III, B-II, C-IV, D-I
- DA-III, B-II, C-I, D-IV
Solution
Given $n=2$, the electronic configurations correspond to elements of the second period.
A. $ns^2 \Rightarrow 2s^2$ is Beryllium (Be).
B. $ns^2np^1 \Rightarrow 2s^2 2p^1$ is Boron (B).
C. $ns^2np^3 \Rightarrow 2s^2 2p^3$ is Nitrogen (N).
D. $ns^2np^6 \Rightarrow 2s^2 2p^6$ is Neon (Ne).
The first ionization energy generally increases across a period from left to right. However, Beryllium has a higher ionization energy than Boron due to the stable fully-filled $2s$ subshell. Nitrogen has a high ionization energy due to its stable half-filled $2p$ subshell. Neon, being a noble gas, has the highest ionization energy.
The order of first ionization energy is B $<$ Be $<$ N $<$ Ne.
Arranging the given values in increasing order: $800 < 899 < 1402 < 2080$ kJ mol$^{-1}$.
Thus, the matching is:
A. Be $\rightarrow 899$ (II)
B. B $\rightarrow 800$ (III)
C. N $\rightarrow 1402$ (IV)
D. Ne $\rightarrow 2080$ (I)
This corresponds to A-II, B-III, C-IV, D-I.
Answer: A-II, B-III, C-IV, D-I
A. $ns^2 \Rightarrow 2s^2$ is Beryllium (Be).
B. $ns^2np^1 \Rightarrow 2s^2 2p^1$ is Boron (B).
C. $ns^2np^3 \Rightarrow 2s^2 2p^3$ is Nitrogen (N).
D. $ns^2np^6 \Rightarrow 2s^2 2p^6$ is Neon (Ne).
The first ionization energy generally increases across a period from left to right. However, Beryllium has a higher ionization energy than Boron due to the stable fully-filled $2s$ subshell. Nitrogen has a high ionization energy due to its stable half-filled $2p$ subshell. Neon, being a noble gas, has the highest ionization energy.
The order of first ionization energy is B $<$ Be $<$ N $<$ Ne.
Arranging the given values in increasing order: $800 < 899 < 1402 < 2080$ kJ mol$^{-1}$.
Thus, the matching is:
A. Be $\rightarrow 899$ (II)
B. B $\rightarrow 800$ (III)
C. N $\rightarrow 1402$ (IV)
D. Ne $\rightarrow 2080$ (I)
This corresponds to A-II, B-III, C-IV, D-I.
Answer: A-II, B-III, C-IV, D-I
Hence, the correct answer is option: 'A'.