Given below are two statements, one is labelled as Statement I and the other is labelled as Statement II. Statement I: C < O < N < F is the correct order in terms of first ionization enthalpy values. Statement II: S Se Te Po O is the correct order in terms of the magnitude of electron gain enthalpy values. In the light of the above statements, choose the correct answer from the options given below :

Both Statement I and Statement II are true.

Statement I is false but Statement II is true

Both Statement I and Statement II are false.

Statement I is true but Statement II is false.

Chemistry · Periodicity of Elements and Periodic Properties

JEE Main 2026 — 22 January, Evening Shift — Question 55

Given below are two statements, one is labelled as Statement I and the other is labelled as Statement II.

Statement I: $\mathrm{C}<\mathrm{O}<\mathrm{N}<\mathrm{F}$ is the correct order in terms of first ionization enthalpy values.

Statement II: $\mathrm{S}>\mathrm{Se}>\mathrm{Te}>\mathrm{Po}>\mathrm{O}$ is the correct order in terms of the magnitude of electron gain enthalpy values.

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

Option A:
Statement I is false but Statement II is true
Option B:
Both Statement I and Statement II are true.
Correct
Option C:
Both Statement I and Statement II are false.
Option D:
Statement I is true but Statement II is false.

Answer: B

Step-by-step solution

Statement I: Across Period 2, ionization enthalpy generally increases. However $\mathrm{N}$ has half-filled $2p^3$ configuration which is extra stable. Thus, $\mathrm{C < O < N < F}$ . This is the correct order. Hence, Statement I is true.

Statement II: In Group 16, electron gain enthalpy (magnitude) decreases down the group. Also $\mathrm{O}$ has lower magnitude than $\mathrm{S}$ due to small size and greater repulsion.

The correct order is $\mathrm{S > Se > Te > Po > O}$ . Thus, Statement II is also true.

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Exam: JEE Main 2026
Paper: 22 January, Evening Shift
Subject: Chemistry
Chapter: Periodicity of Elements and Periodic Properties
Topic: Periodicity in Chemical Properties (Ionization Energy, Electron Affinity, Electronegativity)

Given below are two statements : one is labelled as Statement I and the other is labelled as Statement II : Statement-I : Element X and Y…

Answer: B

Step-by-step solution

Practise Periodicity of Elements and Periodic Properties

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