JEE Main 2018ChemistryClassification of Elements and Periodicity in PropertiesMediumMCQ

JEE Main 2018Classification of Elements and Periodicity in Properties Question with Solution

JEE Main 2018 (15 Apr)

Question

For Na+, Mg2+, F- and O2-, the correct order of increasing ionic radii is:

Choose an option

Show full solutionCorrect option: C
Correct answer
CMg2+<Na+<F-<O2- 

Step-by-step explanation

Isoelectric series:

Mg2+<Na+<F-<O2-

All have 10 electrons. In the isoelectronic series, the proton/electron ratio decreases, so the size decrease because Zeff increases on decrease proton/electron ratio.

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About this question

This is a previous-year question from JEE Main 2018, covering the Classification of Elements and Periodicity in Properties chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.