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JEE Main 2021 · ChemistryMultiple choiceSingle correctEasyRecall

JEE Main 18 March 2021, Shift 1, Chemistry Q34

Question 34 of 90 in this shift, Chemistry question 4 of 30, Section A.

The ionic radius of

\mathrm{Na^+}

ion is 1.02 Å. The ionic radii (in Å) of

\mathrm{Mg^{2+}}

and

\mathrm{Al^{3+}}

, respectively, are :

(1)0.85 and 0.99
(2)0.72 and 0.54Official answer
(3)0.68 and 0.72
(4)1.05 and 0.99

Official answer

Option 2

NTA final key.

Chapter: Classification of Elements and Periodicity in Properties
Topic: Periodic Trends
Idea tested: Isoelectronic Species Radii Comparison

Same idea in other shifts

Asked 2× in all

25 Jul 2021, Shift 1 · Q33The ionic radii of $\mathrm{K^+}$ , $\mathrm{Na^+}$ , $\mathrm{Al^{3+}}$ and $\mathrm{Mg^{2+}}$ are in the order :EasySingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.