Given below are two statements, one is labelled as Statement I and the other is labelled as Statement II. Statement I: The radii of isoelectronic species increases in the order Mg 2+ < Na + < F - < O 2- . Statement II: The magnitude of electron gain enthalpy of halogen decreases in the order Cl F Br I . In the light of the above statements, choose the correct answer from the options given below :

Both Statement I and Statement II are correct

Statement I is incorrect but Statement II is correct

Both Statement I and Statement II are incorrect

Statement I is correct but Statement II is incorrect

Chemistry · Periodicity of Elements and Periodic Properties

JEE Main 2025 — 29 January, Morning Shift — Question 17

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

Statement I: The radii of isoelectronic species increases in the order $\mathrm{Mg}^{2+}<\mathrm{Na}^{+}<\mathrm{F}^{-}<\mathrm{O}^{2-}$ .

Statement II: The magnitude of electron gain enthalpy of halogen decreases in the order $\mathrm{Cl}>\mathrm{F}>\mathrm{Br}>\mathrm{I}$ .

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

For isoelectronic species, radius decreases with increase in nuclear charge.

Since, $Z_{Mg} > Z_{Na} > Z_{F} > Z_{O}$ .

Radius order is $Mg^{2+} < Na^{+} < F^{-} < O^{2-}$

Hence, Statement I is correct.

Electron gain enthalpy trend among halogens follows $Cl > F > Br > I$ . Hence, Statement II is correct.

Therefore, the correct option is D.

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Exam: JEE Main 2025
Paper: 29 January, Morning Shift
Subject: Chemistry
Chapter: Periodicity of Elements and Periodic Properties
Topic: Periodicity in Chemical Properties (Ionization Energy, Electron Affinity, Electronegativity)