Learn

Saturday, 31 October

JEE Main · Chemistry · Classification of Elements and Periodicity in Properties

Isoelectronic Species Radii Comparison

JEE Main asked Isoelectronic Species Radii Comparison 10 times in 10 of the 108 shifts Lumi analysed, in 2020, 2021, 2022, 2023 and 2024. It belongs to Periodic Trends, in Classification of Elements and Periodicity in Properties (Chemistry). The longest wait between two years asking it was 1 year. In 2021, 2022 and 2024 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
10
in 10 shifts
Years
5 of 8
First asked
2020
last in 2024
Pattern
Asked most years
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2020, 2021, 2022, 2023 and 2024. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.10.20’170.08’200.14’210.07’220.07’230.09’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 1 in 12 shifts · 2021: 4 in 24 shifts · 2022: 2 in 24 shifts · 2023: 1 in 12 shifts · 2024: 2 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.

Shift by shift

Each square is one analysed shift, in date order. Open a filled one for that paper.

  • 20260 of 9
  • 20250 of 8
  • 20242 of 18
  • 20231 of 12
  • 20222 of 24
  • 20214 of 24
  • 20201 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Single correct is the usual form. Skill tested: conceptual.

  • Order/ranking of ionic radii
  • Order/values of ionic radii in isoelectronic series

Difficulty

Easy 10Medium 0Hard 0

1 of the 10 questions had a numerical answer.

Every question

All 10 questions

From the official JEE Main shift papers, newest first. Open one for the full question, the options and the official answer.

  1. 1 Feb 2024, Shift 1 · Q65In case of isoelectronic species the size of F−\mathrm{F^-}, Ne and Na+\mathrm{Na^+} is affected by :EasySingle correct
  2. 5 Apr 2024, Shift 1 · Q66The statement(s) that are correct about the species O2−\mathrm{O^{2-}}, F−\mathrm{F^-}, Na+\mathrm{Na^+} and Mg2+\mathrm{Mg^{2+}}. (A) All are…EasyOther
  3. 15 Apr 2023, Shift 1 · Q87The total number of isoelectronic species from the given set is __________. O2−,F−,Al,Mg2+,Na+,O+,Mg,Al3+,F\mathrm{O^{2-}, F^-, Al, Mg^{2+}, Na^+, O^+, Mg, Al^{3+}, F}EasyNumerical value
  4. 27 Jun 2022, Shift 2 · Q65The correct order of increasing ionic radii isEasySingle correct
  5. 27 Jun 2022, Shift 1 · Q65Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The ionic radii…EasyAssertion–reason
  6. 18 Mar 2021, Shift 1 · Q34The ionic radius of Na+\mathrm{Na^+} ion is 1.02 Å. The ionic radii (in Å) of Mg2+\mathrm{Mg^{2+}} and Al3+\mathrm{Al^{3+}}, respectively, are :EasySingle correct
  7. 25 Jul 2021, Shift 2 · Q34The ionic radii of F−\mathrm{F^{-}} and O2−\mathrm{O^{2-}} respectively are 1.33 Å and 1.4 Å, while the covalent radius of N is 0.74 Å. The…EasySingle correct
  8. 25 Jul 2021, Shift 1 · Q33The ionic radii of K+\mathrm{K^+}, Na+\mathrm{Na^+}, Al3+\mathrm{Al^{3+}} and Mg2+\mathrm{Mg^{2+}} are in the order :EasySingle correct
  9. 27 Aug 2021, Shift 2 · Q32The correct order of ionic radii for the ions, P3−\mathrm{P^{3-}}, S2−\mathrm{S^{2-}}, Ca2+\mathrm{Ca^{2+}}, K+\mathrm{K^{+}},…EasySingle correct
  10. 4 Sep 2020, Shift 1 · Q32The ionic radii of O2−\mathrm{O^{2-}}, F−\mathrm{F^-}, Na+\mathrm{Na^+} and Mg2+\mathrm{Mg^{2+}} are in the order :EasySingle correct

Shifts: 4 Sep 2020, Shift 1, 18 Mar 2021, Shift 1, 25 Jul 2021, Shift 2, 25 Jul 2021, Shift 1, 27 Aug 2021, Shift 2, 27 Jun 2022, Shift 2, 27 Jun 2022, Shift 1, 15 Apr 2023, Shift 1, 1 Feb 2024, Shift 1, 5 Apr 2024, Shift 1.

Same topic

Other ideas in Periodic Trends

Periodic Trends has 25 ideas JEE Main has asked; 17 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas