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Saturday, 31 October

JEE Main · Chemistry · The d- and f-Block Elements

Ionization Enthalpy Irregularities

JEE Main asked Ionization Enthalpy Irregularities 4 times in 4 of the 108 shifts Lumi analysed, in 2020, 2021, 2024 and 2026. It belongs to d-Block Elements, in The d- and f-Block Elements (Chemistry). The longest wait between two years asking it was 3 years.

Updated 2026-10-24

Times asked
4
in 4 shifts
Years
4 of 8
First asked
2020
last in 2026
Pattern
Frequent
across the analysed shifts

Questions on this idea a shift, by year

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

00.10.20’170.08’200.03’210’220’230.05’240’250.11’26

Raw count: 2017: 0 in 1 shift · 2020: 1 in 12 shifts · 2021: 1 in 24 shifts · 2022: 0 in 24 shifts · 2023: 0 in 12 shifts · 2024: 1 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
  • 20241 of 18
  • 20230 of 12
  • 20220 of 24
  • 20211 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: recall.

  • Order of ionisation enthalpy of two elements
  • Spin-only moment after ionisation enthalpy

Difficulty

Easy 0Medium 4Hard 0

1 of the 4 questions had a numerical answer.

Every question

All 4 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 2 · Q60The correct order of first (ΔiH1\Delta_iH_1) and second (ΔiH2\Delta_iH_2) ionisation enthalpy values of Cr and Mn are : A. ΔiH1\Delta_iH_1 : Cr…MediumOther
  2. 9 Apr 2024, Shift 2 · Q86A transition metal 'M' among Sc, Ti, V, Cr, Mn and Fe has the highest second ionisation enthalpy. The spin-only magnetic moment value of…MediumNumerical value
  3. 3 Aug 2021, Shift 1 · Q33The correct order of second ionization enthalpy isMediumSingle correct
  4. 8 Jan 2020, Shift 1 · Q36The third ionization enthalpy is minimum for :MediumSingle correct

Shifts: 8 Jan 2020, Shift 1, 3 Aug 2021, Shift 1, 9 Apr 2024, Shift 2, 6 Apr 2026, Shift 2.

Same topic

Other ideas in d-Block Elements

d-Block Elements has 31 ideas JEE Main has asked; 21 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas