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Saturday, 31 October

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

p-Block Ionization Enthalpy Inversions

JEE Main asked p-Block Ionization Enthalpy Inversions 8 times in 8 of the 108 shifts Lumi analysed, in 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 and 2022 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
8
in 8 shifts
Years
4 of 8
First asked
2021
last in 2024
Pattern
Comes in cycles
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 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.

00.10.20’170’200.07’210.14’220.07’230.05’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 2 in 24 shifts · 2022: 4 in 24 shifts · 2023: 1 in 12 shifts · 2024: 1 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
  • 20241 of 18
  • 20231 of 12
  • 20224 of 24
  • 20212 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.

  • Order/ranking of ionization enthalpy
  • First ionization order in group 13

Difficulty

Easy 4Medium 4Hard 0

Every question was multiple choice.

Every question

All 8 questions

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

  1. 4 Apr 2024, Shift 2 · Q67The correct order of the first ionization enthalpy isMediumSingle correct
  2. 11 Apr 2023, Shift 1 · Q64For elements B, C, N, Li, Be, O and F, the correct order of first ionization enthalpy isEasySingle correct
  3. 29 Jun 2022, Shift 2 · Q66Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: The first ionization…EasyAssertion–reason
  4. 29 Jul 2022, Shift 1 · Q64The first ionization enthalpy of Na, Mg and Si, respectively, are : 496, 737 and 786 kJ mol−1\mathrm{mol^{-1}}. The first ionization enthalpy…MediumSingle correct
  5. 27 Jul 2022, Shift 2 · Q66Outermost electronic configurations of four elements A, B, C, D are given below : (A) 3s23s^2 (B) 3s23p13s^23p^1 (C) 3s23p33s^23p^3 (D) 3s23p43s^23p^4…MediumSingle correct
  6. 25 Jul 2022, Shift 2 · Q66The first ionization enthalpies of Be, B, N and O follow the orderEasySingle correct
  7. 26 Feb 2021, Shift 1 · Q33Match List-I with List-II. List-I (Electronic configuration of elements) | List-II (ΔiH\Delta_i H in kJ mol−1^{-1}) (a) 1s2 2s21s^2\ 2s^2 | (i)…MediumMatch the list
  8. 4 Aug 2021, Shift 1 · Q35The correct order of first ionization enthalpy is :EasySingle correct

Shifts: 26 Feb 2021, Shift 1, 4 Aug 2021, Shift 1, 29 Jun 2022, Shift 2, 25 Jul 2022, Shift 2, 27 Jul 2022, Shift 2, 29 Jul 2022, Shift 1, 11 Apr 2023, Shift 1, 4 Apr 2024, Shift 2.

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