/

Learn

Friday, 9 October

/

JEE Main 2021 · ChemistryMultiple choiceSingle correctEasyApplication

JEE Main 25 July 2021, Shift 1, Chemistry Q33

Question 33 of 90 in this shift, Chemistry question 3 of 30, Section A.

The ionic radii of

\mathrm{K^+}

,

\mathrm{Na^+}

,

\mathrm{Al^{3+}}

and

\mathrm{Mg^{2+}}

are in the order :

(1) $\mathrm{K^+<Al^{3+}<Mg^{2+}<Na^+}$
(2) $\mathrm{Na^+<K^+<Mg^{2+}<Al^{3+}}$
(3) $\mathrm{Al^{3+}<Mg^{2+}<Na^+<K^+}$ Official answer
(4) $\mathrm{Al^{3+}<Mg^{2+}<K^+<Na^+}$

Official answer

Option 3

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

18 Mar 2021, Shift 1 · Q34The 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 :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.