Learn

Sunday, 25 October

JEE Main · Chemistry · Class 11

Structure of Atom: JEE Main previous year questions

115 questions in 105 of the 108 JEE Main shifts Lumi analysed, asked in 8 of 8 years. Here is what this chapter tests and how.

Study this chapter
Questions
115
in 105 of 108 shifts · 8 of 8 years
Average a shift
1.1
of 25 Chemistry · 1.1 since 2024 0.1
Typical range
0.9–1.3
questions a shift; fewest 0.8, most 1.7
Weighted estimate
1.2
model, recent years count more · about 4.7 marks
  • Typical range (fact)
  • Average a shift (fact)
  • Weighted estimate (model)

Questions are counted per shift, out of the 25 each subject has, in the shifts Lumi analysed; papers that offered 30 a subject (2017, 2021–2024) are scaled to 25. Typical range: the middle six of the eight years (2017, 2020–2026), leaving out the single highest and lowest year. The average and the range are historical fact. The weighted estimate is a model: each year's share, with recent years counting more (half-life three years), and chapters NTA dropped from the syllabus set near zero. It is a guide to effort, not a forecast of the paper.

What to do

How to spend time on Structure of Atom

Priority

Should do

One of the 6 Chemistry chapters that took Chemistry from half to 80% of its questions in the 108 shifts analysed. How bands are set

Past questions
115in 105 of 108 shifts
Study plan gives it
19 hover 12 months; 14 h over 6
Study this chapter →

Ideas asked most often

  1. Aufbau Principle and n+l Rule8×
  2. Bohr Radius Calculation8×
  3. Calculation of Radial and Angular Nodes8×
  4. Magnetic Quantum Number7×
  5. Ionization and Excitation Energy6×

44 of the 96 ideas in Lumi’s map of this chapter have not been asked or touched in the shifts analysed. Of its idea-tagged questions from 2024 on, 28% tested an idea not asked in an earlier year, so learn the whole chapter, not just the list above.

Within each subject, chapters in NTA's 2026 syllabus are ranked by their average questions a shift over all 8 years analysed (history, not the model). Going down that list, the chapters that together held the first half of the subject's questions are Must do; the next ones, up to 80%, are Should do; the rest are Lower priority.

Key findings

Structure of Atom at a glance

  1. 01

    72%

    of its 36 questions from 2024 on that Lumi matched to an idea tested one JEE Main had asked in an earlier year; 100% came from a topic asked in an earlier year.

  2. 02

    46%

    of the 96 ideas in Lumi's map of the chapter have not been asked or touched on in the shifts analysed.

  3. 03

    45%

    of its questions asked for a numerical answer, 1.5 times the Chemistry average.

  4. 04

    3%

    of its questions were rated hard, against 6% across all Chemistry questions in the same shifts.

Questions a shift, year by year

Out of the 25 Chemistry questions in a shift. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift.

0241.7’170.8’200.9’210.9’220.9’230.9’241.1’251.3’26

Raw count: 2017: 2 in 1 shift · 2020: 10 in 12 shifts · 2021: 25 in 24 shifts · 2022: 25 in 24 shifts · 2023: 13 in 12 shifts · 2024: 19 in 18 shifts · 2025: 9 in 8 shifts · 2026: 12 in 9 shifts.

Kind of question

SHARE OF QUESTIONS
  • Numerical answer45%
  • Calculation17%
  • Application15%
  • Conceptual8%
  • Diagram based4%
  • Two statements4%
  • Multi-step3%
  • Recall, single correct2%
  • Match the list2%
  • Assertion–reason2%

Most common asks: order/ranking of orbital energies (4); count correct statements on atomic structure (4); count electrons with given quantum numbers (2).

Profile

This chapter in numbers

Where it ranks, how steady it is, and what it costs to study.

Rank, all JEE chapters
#28
of 70 by weighted estimate
Rank in Chemistry
#14
of 21 chapters
Share of Chemistry
4.2%
of its questions, all shifts analysed
Busiest year
2017
1.7 questions a shift
Year to year
Some swing
varies by about 0.3 questions a shift
Long-run direction
-0.03
questions a shift, per year
Easy questions
57%
3% rated hard
Numerical answer
45%
1.5× the Chemistry rate
With a figure
10%
graph, diagram or structure
Study time
19 h
14 h on a 6-month plan
Marks per study hour
0.25
#18 of 70 chapters
Foundation for others
99%
of its ideas are used in other chapters

Difficulty, year by year

Each question rated easy, medium or hard. Each bar is that year’s split, so years compare directly; the number is the questions in that year’s analysed shifts (1 to 24 shifts a year).

  • 20172
  • 202010
  • 202125
  • 202225
  • 202313
  • 202419
  • 20259
  • 202612
  • Easy
  • Medium
  • Hard

What it asks you to do

SHARE OF QUESTIONS
  • Calculation50%
  • Application18%
  • Conceptual17%
  • Multi-step5%
  • Data or graph5%
  • Recall3%

Coverage

How much of the chapter JEE Main has used

We split the chapter into 96 ideas. In the 108 shifts analysed, JEE Main built a question around 37 of them. Most of the chapter has never been the main idea of a question, so past questions alone leave most of it out.

Asked as the main idea
37
Touched on in a question
15
Never asked
44

Topics

What repeats, topic by topic

This chapter's questions per topic in each year's analysed shifts. The number is the count; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. 20 questions had no close topic in Lumi's map and count for the chapter only.

’17’20’21’22’23’24’25’26
012+questions in that year’s analysed shifts, shaded per shift
  • Quantum Numbers

    As a topic: 52 questions in 8 of 8 years, most often single correct, 29% numerical answer. Recent asks: match list on orbital nodes; count correct statements on atomic structure; count correct statements on orbitals.

  • Bohr's Atomic Theory

    As a topic: 39 questions in 8 of 8 years, most often numerical value, 46% numerical answer.

  • Photoelectric Effect

    As a topic: 66 questions in 7 of 8 years, most often single correct, 18% numerical answer. Recent asks: spectrum region from power and photon rate; work function from two wavelength data; numerical: work function from stopping potential.

  • Matter Waves

    As a topic: 55 questions in 8 of 8 years, most often single correct, 11% numerical answer.

Drill down

Topic, idea, question

Open a topic to see every idea JEE Main tested inside it, then open an idea to read the questions. Each row shows its 8 years.

  • Open46 · 40%210123955

    20 ideas inside

    • OpenRepeated8 · 17%32
    • OpenRepeated7 · 15%23
    • OpenRepeated7 · 15%32
    • OpenRepeated4 · 9%
    • Open3 · 7%3
    • OpenRepeated2 · 4%
    • Open2 · 4%2
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
  • Open39 · 34%7745636
  • Open6 · 5%32
  • Open3 · 3%
  • Open1 · 1%

Squares are the 8 years with analysed shifts, 2017 to 2026. A number is the questions that year when there is more than one; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. Share is of the level above.

Ideas

The exact ideas JEE Main has asked

Inside the topics, 34 different ideas were tested; 17 came more than once. These are the repeats, then the ideas new since 2024.

Dots are the 8 years with analysed shifts, 2017 to 2026.

Every question

All 115 Structure of Atom questions

Newest first, shift by shift. The newest 40 show their opening words; older ones name the idea they tested. Each opens with its options and the official answer.

JEE Main 202612 questions

  1. 2 Apr 2026, Shift 1 · Q52What is the energy (in J atom−1\mathrm{J\ atom^{-1}}) required for the following process ? Li2+(g)→Li3+(g)+e−\mathrm{Li^{2+}(g)\rightarrow Li^{3+}(g)+e^-} (Take…EasySingle correct
  2. 2 Apr 2026, Shift 2 · Q71The surface of sodium metal is irradiated with radiation of wavelength xx nm. The kinetic energy of ejected electrons is…EasyNumerical value
  3. 4 Apr 2026, Shift 1 · Q52What is the ratio of wave number of first line (lowest energy line) of Balmer series of H atomic spectrum to first line of its Brackett…MediumSingle correct
  4. 4 Apr 2026, Shift 1 · Q53Which of the following is correct set of 44 quantum numbers of 19th19^{\text{th}} electron in Chromium (Atomic number =24=24) in accordance…MediumSingle correct
  5. 4 Apr 2026, Shift 2 · Q52The species having identical radii according to the Bohr's theory are: A. H (first orbit) B. He+\mathrm{He^+} (first orbit) C.…EasyOther
  6. 5 Apr 2026, Shift 1 · Q52Arrange the following atomic orbitals of multi electron atoms in order of increasing energy. A. n=3,l=2,m=+1n = 3, l = 2, m = +1 B.…MediumOther
  7. 5 Apr 2026, Shift 1 · Q53Identify the correct statements from the following : A. Heisenberg uncertainty principle is applicable to electrons. B. The size of 2px2p_x…EasyOther
  8. 5 Apr 2026, Shift 2 · Q52Which of the following statement(s) is/are true ? A. If two orbitals have the same value of (n+l)(n+l), the orbital with lower value of n…MediumOther
  9. 6 Apr 2026, Shift 1 · Q52If shortest wavelength of hydrogen atom in Lyman series is xx, then longest wavelength in Balmer series of He+\mathrm{He^+} is:MediumSingle correct
  10. 6 Apr 2026, Shift 1 · Q53Match the LIST-I with LIST-II List-I (Orbital) | List-II (Radial nodes and nodal plane) A. 2s | I. 1 Radial node + two nodal planes B. 3s…MediumMatch the list
  11. 6 Apr 2026, Shift 2 · Q52The Bohr radius of a hydrogen like species is 70.53 pm. The species and the stationary state (nn) are respectively (Given : Hydrogen atom…EasySingle correct
  12. 8 Apr 2026, Shift 2 · Q73Consider two radiations of wavelengths 1. λ1=2000\lambda_1 = 2000 Å 2. λ2=6000\lambda_2 = 6000 Å The ratio of the energies of these two radiations…EasyNumerical value

JEE Main 20259 questions

  1. 2 Apr 2025, Shift 1 · Q52According to Bohr's model of hydrogen atom, which of the following statement is incorrect ?EasySingle correct
  2. 2 Apr 2025, Shift 2 · Q52Which of the following statements are true ? (A) The subsidiary quantum number ll describes the shape of the orbital occupied by the…MediumOtherHas a figure
  3. 3 Apr 2025, Shift 1 · Q52Which of the following postulate of Bohr's model of hydrogen atom is not in agreement with quantum mechanical model of an atom?EasySingle correct
  4. 3 Apr 2025, Shift 2 · Q52For electrons in '2s' and '2p' orbitals, the orbital angular momentum values, respectively are :EasySingle correct
  5. 4 Apr 2025, Shift 2 · Q51Consider the ground state of chromium atom (Z=24)(Z=24). How many electrons are with Azimuthal quantum number l=1l=1 and l=2l=2 respectively ?EasySingle correct
  6. 7 Apr 2025, Shift 1 · Q52Which of the following statements are correct, if the threshold frequency of caesium is 5.16×10145.16 \times 10^{14} Hz? A. When Cs is placed…MediumOtherHas a figure
  7. 7 Apr 2025, Shift 2 · Q51The extra stability of half-filled subshell is due to : (A) Symmetrical distribution of electrons (B) Smaller coulombic repulsion energy…MediumOther
  8. 8 Apr 2025, Shift 2 · Q51Correct statements for an element with atomic number 9 are A. There can be 5 electrons for which ms=+12m_s = +\frac{1}{2} and 4 electrons for…MediumOther
  9. 8 Apr 2025, Shift 2 · Q72The energy of an electron in first Bohr orbit of H-atom is −13.6 eV. The magnitude of energy value of electron in the first excited state…EasyNumerical value

JEE Main 202419 questions

  1. 4 Apr 2024, Shift 1 · Q81The de-Broglie's wavelength of an electron in the 4th4^{\mathrm{th}} orbit is ________ πa0\pi a_0. (a0a_0 = Bohr's radius)MediumNumerical value
  2. 4 Apr 2024, Shift 2 · Q81The maximum number of orbitals which can be identified with n = 4 and mlm_l = 0 is ________.EasyNumerical value
  3. 5 Apr 2024, Shift 1 · Q81The value of Rydberg constant (RH\mathrm{R_H}) is 2.18×10−182.18 \times 10^{-18} J. The velocity of electron having mass 9.1×10−319.1 \times 10^{-31} kg…MediumNumerical value
  4. 5 Apr 2024, Shift 2 · Q81In an atom, total number of electrons having quantum numbers n=4n=4, ∣ml∣=1|m_l|=1 and ms=−12m_s=-\frac{1}{2} is ________.MediumNumerical value
  5. 6 Apr 2024, Shift 1 · Q81Frequency of the de-Broglie wave of electron in Bohr's first orbit of hydrogen atom is __________ ×1013\times 10^{13} Hz (nearest integer).…MediumNumerical value
  6. 6 Apr 2024, Shift 2 · Q81For hydrogen atom, energy of an electron in first excited state is −3.4-3.4 eV, K.E. of the same electron of hydrogen atom is xx eV. Value…EasyNumerical value
  7. 8 Apr 2024, Shift 1 · Q81A hypothetical electromagnetic wave is show below. [figure: sinusoidal wave along an axis with a distance marked 1.5 pm between two dashed…EasyNumerical valueHas a figure
  8. 8 Apr 2024, Shift 2 · Q82Wavenumber for a radiation having 5800 A˚\mathrm{\AA} wavelength is x×10 cm−1x \times 10\ \mathrm{cm^{-1}}. The value of xx is ______. (Integer…EasyNumerical value
  9. 9 Apr 2024, Shift 1 · Q61Compare the energies of following sets of quantum numbers for multielectron system. (A) n=4,l=1n=4, l=1 (B) n=4,l=2n=4, l=2 (C) n=3,l=1n=3, l=1 (D)…EasySingle correct
  10. 9 Apr 2024, Shift 2 · Q81Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron to be found within an atomic nucleus of…EasyNumerical value
  11. 1 Feb 2024, Shift 1 · Q61According to the wave-particle duality of matter by de-Broglie, which of the following graph plot presents most appropriate relationship…EasyDiagram basedHas a figure
  12. 1 Feb 2024, Shift 2 · Q61The number of radial node/s for 3p orbital is :EasySingle correct
  13. 27 Jan 2024, Shift 1 · Q82The number of electrons present in all the completely filled subshells having n=4n = 4 and s=+12s = +\frac{1}{2} is __________. (Where nn =…MediumNumerical value
  14. 29 Jan 2024, Shift 1 · Q61The correct set of four quantum numbers for the valence electron of rubidium atom (Z = 37) is :EasySingle correct
  15. 30 Jan 2024, Shift 1 · Q61Given below are two statements : Statement (I) : The orbitals having same energy are called as degenerate orbitals. Statement (II) : In…EasyTwo statements
  16. 30 Jan 2024, Shift 1 · Q66Match List - I with List - II. List - I (Species) List - II (Electronic distribution) (A) Cr+2\mathrm{Cr^{+2}} (I) 3d83d^8 (B)…MediumMatch the list
  17. 30 Jan 2024, Shift 2 · Q81Number of spectral lines obtained in He+\mathrm{He^+} spectra, when an electron makes transition from fifth excited state to first excited…EasyNumerical value
  18. 31 Jan 2024, Shift 1 · Q82The ionization energy of sodium in kJ mol−1^{-1}, if electromagnetic radiation of wavelength 242 nm is just sufficient to ionize sodium…MediumNumerical value
  19. 31 Jan 2024, Shift 2 · Q62The four quantum numbers for the electron in the outer most orbital of potassium (atomic no. 19) areEasySingle correct

JEE Main 202313 questions

  1. 6 Apr 2023, Shift 1 · Q82Open the question · Easy · Numerical value
  2. 6 Apr 2023, Shift 2 · Q62Circumference and De Broglie Wavelength · Easy · Single correct
  3. 8 Apr 2023, Shift 1 · Q82Open the question · Easy · Numerical value
  4. 8 Apr 2023, Shift 2 · Q64Moseley's Law Graph Analysis · Easy · Diagram based · has a figure
  5. 8 Apr 2023, Shift 2 · Q81Calculation of Radial and Angular Nodes · Easy · Numerical value
  6. 10 Apr 2023, Shift 1 · Q82Open the question · Medium · Numerical value
  7. 10 Apr 2023, Shift 2 · Q81Ionization and Excitation Energy · Medium · Numerical value · has a figure
  8. 11 Apr 2023, Shift 1 · Q61Open the question · Medium · Assertion–reason
  9. 11 Apr 2023, Shift 2 · Q83Interpreting Radial Probability Curves · Medium · Numerical value
  10. 12 Apr 2023, Shift 1 · Q82Photoelectric Effect Coupling · Easy · Numerical value · has a figure
  11. 13 Apr 2023, Shift 1 · Q61Total, Kinetic, and Potential Energy · Easy · Single correct
  12. 13 Apr 2023, Shift 2 · Q83Orbital and Spin Angular Momentum · Easy · Numerical value
  13. 15 Apr 2023, Shift 1 · Q62Angular Momentum Quantization · Easy · Two statements

JEE Main 202225 questions

  1. 25 Jul 2022, Shift 1 · Q62Validity of Quantum Number Sets · Easy · Single correct
  2. 25 Jul 2022, Shift 2 · Q83Number of Spectral Lines in Transitions · Easy · Numerical value
  3. 26 Jul 2022, Shift 1 · Q83Basic Wavelength-Momentum Relation · Easy · Numerical value
  4. 26 Jul 2022, Shift 2 · Q82Open the question · Easy · Numerical value
  5. 27 Jul 2022, Shift 1 · Q63Open the question · Medium · Assertion–reason
  6. 27 Jul 2022, Shift 2 · Q61Aufbau Principle and n+l Rule · Easy · Single correct
  7. 28 Jul 2022, Shift 1 · Q61Magnetic Quantum Number · Medium · Single correct
  8. 28 Jul 2022, Shift 2 · Q38Configurations of Isoelectronic Species · Medium · Single correct
  9. 28 Jul 2022, Shift 2 · Q53Ionization and Excitation Energy · Medium · Numerical value
  10. 29 Jul 2022, Shift 1 · Q83Open the question · Medium · Numerical value
  11. 29 Jul 2022, Shift 2 · Q62Aufbau Principle and n+l Rule · Medium · Single correct
  12. 30 Jul 2022, Shift 2 · Q32Open the question · Easy · Single correct
  13. 24 Jun 2022, Shift 1 · Q62Hydrogen vs Multi-Electron Degeneracy · Easy · Other
  14. 24 Jun 2022, Shift 2 · Q62Open the question · Easy · Single correct
  15. 25 Jun 2022, Shift 1 · Q83Ionization and Excitation Energy · Medium · Numerical value
  16. 25 Jun 2022, Shift 2 · Q61Work Function and Threshold · Easy · Single correct
  17. 26 Jun 2022, Shift 1 · Q63Bohr Radius Calculation · Easy · Single correct
  18. 26 Jun 2022, Shift 2 · Q61Calculation of Radial and Angular Nodes · Easy · Single correct
  19. 27 Jun 2022, Shift 1 · Q82Open the question · Medium · Numerical value
  20. 27 Jun 2022, Shift 2 · Q82Validity of Quantum Number Sets · Easy · Numerical value
  21. 28 Jun 2022, Shift 1 · Q82Work Function and Threshold · Easy · Numerical value
  22. 28 Jun 2022, Shift 2 · Q62Validity of Quantum Number Sets · Easy · Other
  23. 29 Jun 2022, Shift 1 · Q62Anomalous Electron Configurations · Easy · Other
  24. 29 Jun 2022, Shift 2 · Q62Interpreting Radial Wavefunction Graphs · Medium · Diagram based · has a figure
  25. 30 Jun 2022, Shift 1 · Q62Calculation of Radial and Angular Nodes · Easy · Single correct

JEE Main 202125 questions

  1. 3 Aug 2021, Shift 1 · Q52Open the question · Hard · Numerical value · has a figure
  2. 3 Aug 2021, Shift 2 · Q53Bohr Radius Calculation · Easy · Numerical value
  3. 4 Aug 2021, Shift 1 · Q52Basic Wavelength-Momentum Relation · Easy · Numerical value
  4. 4 Aug 2021, Shift 2 · Q53Photon Flux and Beam Power · Easy · Numerical value
  5. 26 Aug 2021, Shift 1 · Q32Electron Velocity in Orbit · Medium · Two statements
  6. 26 Aug 2021, Shift 2 · Q52Einstein's Photoelectric Equation · Easy · Numerical value
  7. 27 Aug 2021, Shift 1 · Q51Angular Momentum Quantization · Hard · Numerical value
  8. 27 Aug 2021, Shift 1 · Q57Anomalous Configurations of Heavy Metals · Medium · Numerical value
  9. 27 Aug 2021, Shift 2 · Q53Photon Energy and Momentum · Easy · Numerical value
  10. 31 Aug 2021, Shift 1 · Q52Magnetic Quantum Number · Medium · Numerical value
  11. 31 Aug 2021, Shift 2 · Q53Magnetic Quantum Number · Easy · Numerical value
  12. 24 Feb 2021, Shift 1 · Q53Circumference and De Broglie Wavelength · Medium · Numerical value
  13. 24 Feb 2021, Shift 2 · Q31Total, Kinetic, and Potential Energy · Medium · Single correct
  14. 25 Feb 2021, Shift 1 · Q31Interpreting Radial Probability Distribution Graphs · Medium · Diagram based · has a figure
  15. 25 Feb 2021, Shift 2 · Q53Ionization and Excitation Energy · Medium · Numerical value
  16. 26 Feb 2021, Shift 1 · Q31Calculation of Radial and Angular Nodes · Easy · Single correct
  17. 26 Feb 2021, Shift 2 · Q53Open the question · Medium · Numerical value
  18. 22 Jul 2021, Shift 2 · Q53Aufbau Principle and n+l Rule · Easy · Numerical value
  19. 25 Jul 2021, Shift 1 · Q53Open the question · Medium · Numerical value
  20. 25 Jul 2021, Shift 2 · Q53Open the question · Medium · Numerical value
  21. 16 Mar 2021, Shift 2 · Q53Magnetic Quantum Number · Easy · Numerical value
  22. 17 Mar 2021, Shift 1 · Q53Calculation of Radial and Angular Nodes · Medium · Numerical value
  23. 17 Mar 2021, Shift 2 · Q53Counting Unpaired Electrons · Easy · Numerical value
  24. 18 Mar 2021, Shift 1 · Q32Calculation of Radial and Angular Nodes · Easy · Single correct
  25. 18 Mar 2021, Shift 2 · Q32Limitations of Bohr's Model · Easy · Two statements

JEE Main 202010 questions

  1. 8 Jan 2020, Shift 1 · Q30Longest and Shortest Wavelengths in a Series · Medium · Other
  2. 8 Jan 2020, Shift 2 · Q29Bohr Radius Calculation · Easy · Single correct
  3. 9 Jan 2020, Shift 1 · Q26Angular Momentum Quantization · Easy · Single correct
  4. 2 Sep 2020, Shift 1 · Q30Open the question · Medium · Diagram based · has a figure
  5. 2 Sep 2020, Shift 2 · Q30Magnetic Quantum Number · Medium · Single correct
  6. 2 Sep 2020, Shift 2 · Q46Photoelectric Effect Coupling · Easy · Numerical value
  7. 3 Sep 2020, Shift 2 · Q30Azimuthal Quantum Number · Hard · Single correct
  8. 4 Sep 2020, Shift 1 · Q31Electromagnetic Regions of Spectral Series · Easy · Single correct
  9. 4 Sep 2020, Shift 2 · Q31Rydberg Formula and Transitions · Medium · Single correct
  10. 5 Sep 2020, Shift 1 · Q41Bohr Radius Calculation · Medium · Single correct

JEE Main 20172 questions

  1. 2 Apr 2017 (offline) · Q38Bohr Radius Calculation · Easy · Single correct
  2. 2 Apr 2017 (offline) · Q49Open the question · Medium · Single correct

Questions from the official JEE Main papers published by NTA. Chapter, topic and idea tags, counts and notes are Lumi’s. Pattern: Asked most years.

More Chemistry, Class 11

All JEE Main chaptersJEE Main Chemistry analysisStudy plan