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Saturday, 31 October

JEE Main · Chemistry · Chemical Bonding and Molecular Structure

Isoelectronic and Isostructural Principle

JEE Main asked Isoelectronic and Isostructural Principle 2 times in 2 of the 108 shifts Lumi analysed, in 2022 and 2026. It belongs to VSEPR Theory, in Chemical Bonding and Molecular Structure (Chemistry). The longest wait between two years asking it was 4 years.

Updated 2026-10-24

Times asked
2
in 2 shifts
Years
2 of 8
First asked
2022
last in 2026
Pattern
Occasional
across the analysed shifts

Questions on this idea a shift, by year

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

00.10.20’170’200’210.03’220’230’240’250.11’26

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

Shift by shift

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

  • 20261 of 9
  • 20250 of 8
  • 20240 of 18
  • 20230 of 12
  • 20221 of 24
  • 20210 of 24
  • 20200 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.

  • Odd-one-out among species pairs
  • Isoelectronic and shape of related species

Difficulty

Easy 1Medium 1Hard 0

Every question was multiple choice.

Every question

All 2 questions

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

  1. 6 Apr 2026, Shift 1 · Q54The pairs among A=[SO32−,CO32−]\mathrm{A}=\left[\mathrm{SO_3^{2-},CO_3^{2-}}\right], B=[O22−,F2]\mathrm{B}=\left[\mathrm{O_2^{2-},F_2}\right],…MediumSingle correct
  2. 29 Jun 2022, Shift 2 · Q63Consider the species CH4\mathrm{CH_4}, NH4+\mathrm{NH_4^{+}} and BH4−\mathrm{BH_4^{-}}. Choose the correct option with respect to the there…EasySingle correct

Shifts: 29 Jun 2022, Shift 2, 6 Apr 2026, Shift 1.

Same topic

Other ideas in VSEPR Theory

VSEPR Theory has 25 ideas JEE Main has asked; 13 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas