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Saturday, 31 October

JEE Main · Physics · Atoms

Identifying Atomic Number from Spectra

JEE Main asked Identifying Atomic Number from Spectra 2 times in 2 of the 108 shifts Lumi analysed, in 2020 and 2024. It belongs to Bohr's Atomic Model, in Atoms (Physics). 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
2020
last in 2024
Pattern
Occasional
across the analysed shifts

Questions on this idea a shift, by year

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

00.050.10’170.08’200’210’220’230.05’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 1 in 12 shifts · 2021: 0 in 24 shifts · 2022: 0 in 24 shifts · 2023: 0 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
  • 20230 of 12
  • 20220 of 24
  • 20210 of 24
  • 20201 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Numerical value is the usual form. Skill tested: calculation.

  • Wavelength of transition in hydrogen-like ion
  • Hydrogen-like ion line frequency ratio

Difficulty

Easy 0Medium 2Hard 0

1 of the 2 questions had a numerical answer.

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. 1 Feb 2024, Shift 2 · Q60A particular hydrogen - like ion emits the radiation of frequency 3×10153\times10^{15} Hz when it makes transition from n = 2 to n = 1. The…MediumNumerical value
  2. 9 Jan 2020, Shift 2 · Q19The energy required to ionise a hydrogen like ion in its ground state is 9 Rydbergs. What is the wavelength of the radiation emitted when…MediumSingle correct

Shifts: 9 Jan 2020, Shift 2, 1 Feb 2024, Shift 2.

Same topic

Other ideas in Bohr's Atomic Model

Bohr's Atomic Model has 22 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