NEET UG · Chemistry · Structure of Atom

Quantum Numbers: NEET previous year questions

16 questions in ten years of NEET, in 10 of 10 papers. Pattern: Every year. Here is how it is asked and which ideas come back.

Asked in 10 years: 16; about 1.5 per paper
Years asked: 10/10; last asked 2026
Chance of a question next paper: 84%; historical rate, how we compute it
Weighted estimate: 1.6; model; history: 1.5 a paper on average, typically 1–2

Key findings

01
Asked in 10 of 10 papers, 16 questions in all: #28 of 204 topics by ten-year total.
02
80% of its questions since 2018 tested an idea never asked before; 2 repeated an idea from the year before.
03
The most repeated idea is Single-Electron Species Energy Exception, asked 3 times (2024, 2025), usually as “numerical”.
04
NEET has asked 8 of the 84 ideas in this topic; 66 have never been asked, directly or indirectly.
05
Mostly asked as one-line MCQ (50%); 44% easy, 0% hard.

Questions per year

Up to 2023: 1.5; per paper
Since 2024: 1.6; 0.1
Usual gap: 1.0 yrs; between papers asking it
Swing: ±0.4; questions, year to year

Recent framings

graph interpretation of radial nodes
numerical: ratio of wavelengths for hydrogen transitions
numerical: Bohr energy and radius of hydrogen-like ions

Revise first

Single-Electron Species Energy Exception (2024 2025); Graphical Identification of Radial Nodes (2026); Azimuthal Quantum Number (l) (2024)

How it is asked

Difficulty, format and skill

Across all 16 questions on Quantum Numbers since 2017.

Difficulty

QUESTIONS

Easy7 · 44%
Medium9 · 56%
Hard0 · 0%

Format

One-line MCQ · 8 Q50%
Numerical · 5 Q31%
Figure-based · 1 Q6%
Match the lists · 1 Q6%
Other · 1 Q6%

Skill tested

Calculation · 5 Q31%
Recall · 4 Q25%
Concept · 4 Q25%
Application · 2 Q13%
Data or graph · 1 Q6%

Repeats

New idea, or one asked before?

Each column is a paper. Blue questions tested an idea NEET had not asked before; navy ones went back to an idea from an earlier paper. 2017 is the first paper, so everything in it counts as new.

’17’18’19’20’21’22’23’24’25’26

Idea asked for the first time
Idea asked in an earlier paper

Coverage of the topic

NEET has asked 8 of the 84 ideas in this topic. 66 have never been asked yet.

81066

Asked directly8 · 10%
Touched inside another question10 · 12%
Never asked66 · 79%

Ideas come from Lumi’s syllabus map of NCERT. A never-asked idea is not a safe skip: most new questions come from exactly these.

Drill down

Idea, year, question

Every idea NEET tested in this topic, with its ten papers. Open one to read the questions.

ideaAskedShareYears’17’18’19’20’21’22’23’24’25’26

Repeated3 · 19%19%2/102
- 2025 · Q46
  The ratio of the wavelengths of the light absorbed by a Hydrogen atom when it undergoes $n = 2 \to n = 3$ and $n = 4 \to n = 6$ …
  mediumNumericalAsked the year before
- 2025 · Q50
  Energy and radius of first Bohr orbit of $He^+$ and $Li^{2+}$ are [Given $R_H = 2.18\times10^{-18}$ J, $a_0$ = 52.9 pm]
  mediumNumericalAsked the year before
- 2024 · Q57
  The energy of an electron in the ground state (n = 1) for He $^+$ ion is $-x$ J, then that for an electron in n = 2 state for Be $^{3+}$ ion…
  mediumNumericalNew idea
Repeated2 · 13%13%2/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10

Squares are the ten papers, 2017 to 2026; darker means more questions. Share is of the level above.

Ideas

Every idea inside this topic

13 different ideas were tested; 2 came more than once. Azimuthal Quantum Number (l) is the foundation for 73 other ideas in the syllabus.

Single-Electron Species Energy Exception3×
numerical
Numerical · 11% next · foundation for 1
Orbital Degeneracy2×
identify incorrect statement on orbitals
One-line MCQ · 6% next
Graphical Identification of Radial Nodes1×
graph interpretation of radial nodes
Figure-based · 6% next
Azimuthal Quantum Number (l)1×
match list on quantum numbers
Match the lists · 6% next · foundation for 73
Fundamental Particles and Early Atomic Models1×
select correct statements on atomic structure
Other · 4% next
Magnetic Quantum Number (ml)1×
relation between quantum numbers
One-line MCQ · 4% next · foundation for 37
Bohr Orbit Radius1×
numerical
Numerical · 4% next
Isoelectronic Species Configurations1×
identify non isoelectronic pair of ions
One-line MCQ · 4% next
Wave Nature of Electromagnetic Radiation1×
numerical
Numerical · 4% next
Atomic Number, Mass Number and Particle Counts1×
numerical
One-line MCQ · 4% next
Hydrogen Spectral Series1×
identify spectral series by region
One-line MCQ · 4% next
The (n+l) Rule1×
order/ranking of property
One-line MCQ · 4% next · foundation for 3
Electronic Filling Rules1×
incorrect statement on atomic structure
One-line MCQ · 4% next · foundation for 27

Idea	Times	Format	Chance next	Foundation for
Single-Electron Species Energy Exceptionnumerical	3	NumericalCalculation	11%	1 ideas
Orbital Degeneracyidentify incorrect statement on orbitals	2	One-line MCQConcept	6%	–
Graphical Identification of Radial Nodesgraph interpretation of radial nodes	1	Figure-basedData or graph	6%	–
Azimuthal Quantum Number (l)match list on quantum numbers	1	Match the listsRecall	6%	73 ideas
Fundamental Particles and Early Atomic Modelsselect correct statements on atomic structure	1	OtherRecall	4%	–
Magnetic Quantum Number (ml)relation between quantum numbers	1	One-line MCQConcept	4%	37 ideas
Bohr Orbit Radiusnumerical	1	NumericalCalculation	4%	–
Isoelectronic Species Configurationsidentify non isoelectronic pair of ions	1	One-line MCQApplication	4%	–
Wave Nature of Electromagnetic Radiationnumerical	1	NumericalCalculation	4%	–
Atomic Number, Mass Number and Particle Countsnumerical	1	One-line MCQRecall	4%	–
Hydrogen Spectral Seriesidentify spectral series by region	1	One-line MCQRecall	4%	–
The (n+l) Ruleorder/ranking of property	1	One-line MCQApplication	4%	3 ideas
Electronic Filling Rulesincorrect statement on atomic structure	1	One-line MCQConcept	4%	27 ideas

Chance next is the historical rate at which an idea with this record came back in the following paper. It is low for every idea, which is why learning the topic beats memorising past questions. All repeated ideas

Every question

Quantum Numbers questions, year by year

The opening words of each question as it appeared in the official paper, with the idea it tested.

NEET 20261 question

Q88
Consider the following schematic plots of orbital wavefunction ( $\psi_r$ ) against distance (r) from the nucleus. [Figure: four plots A, B,…
Idea: Graphical Identification of Radial Nodes
New ideaMediumFigure-based · figure

NEET 20252 questions

Q46
The ratio of the wavelengths of the light absorbed by a Hydrogen atom when it undergoes $n = 2 \to n = 3$ and $n = 4 \to n = 6$ …
Idea: Single-Electron Species Energy Exception
Asked last yearMediumNumerical
Q50
Energy and radius of first Bohr orbit of $He^+$ and $Li^{2+}$ are [Given $R_H = 2.18\times10^{-18}$ J, $a_0$ = 52.9 pm]
Idea: Single-Electron Species Energy Exception
Asked last yearMediumNumerical

NEET 20242 questions

Q56
Match List I with List II. List I (Quantum Number) | List II (Information provided) A. $m_l$ | I. shape of orbital B. $m_s$ | II. size of…
Idea: Azimuthal Quantum Number (l)
New ideaEasyMatch the lists
Q57
The energy of an electron in the ground state (n = 1) for He $^+$ ion is $-x$ J, then that for an electron in n = 2 state for Be $^{3+}$ ion…
Idea: Single-Electron Species Energy Exception
New ideaMediumNumerical

NEET 20232 questions

Q74
Select the correct statements from the following : A. Atoms of all elements are composed of two fundamental particles. B. The mass of the…
Idea: Fundamental Particles and Early Atomic Models
New ideaEasyOther
Q78
The relation between $n_m$ , ( $n_m$ = the number of permissible values of magnetic quantum number (m)) for a given value of azimuthal…
Idea: Magnetic Quantum Number (ml)
New ideaEasyOne-line MCQ

NEET 20222 questions

Q70
Identify the incorrect statement from the following
Idea: Orbital Degeneracy
MediumOne-line MCQ
Q86
If radius of second Bohr orbit of the $\mathrm{He^+}$ ion is 105.8 pm, what is the radius of third Bohr orbit of $\mathrm{Li^{2+}}$ ion ?
Idea: Bohr Orbit Radius
New ideaMediumNumerical

NEET 20212 questions

Q57
A particular station of All India Radio, New Delhi, broadcasts on a frequency of 1,368 kHz (kilohertz). The wavelength of the…
Idea: Wave Nature of Electromagnetic Radiation
New ideaEasyNumerical
Q95
From the following pairs of ions which one is not an iso-electronic pair ?
Idea: Isoelectronic Species Configurations
New ideaEasyOne-line MCQ

NEET 20201 question

Q124
The number of protons, neutrons and electrons in $^{175}_{71}\mathrm{Lu}$ , respectively, are :
Idea: Atomic Number, Mass Number and Particle Counts
New ideaEasyOne-line MCQ

NEET 20192 questions

Q49
4d, 5p, 5f and 6p orbitals are arranged in the order of decreasing energy. The correct option is :
Idea: The (n+l) Rule
New ideaMediumOne-line MCQ
Q87
Which of the following series of transitions in the spectrum of hydrogen atom falls in visible region ?
Idea: Hydrogen Spectral Series
New ideaEasyOne-line MCQ

NEET 20181 question

Q90
Which one is a wrong statement ?
Idea: Electronic Filling Rules
New ideaMediumOne-line MCQ · figure

NEET 20171 question

Q59
Which one is the wrong statement ?
Idea: Orbital Degeneracy
MediumOne-line MCQ

Questions from the official NEET UG papers published by NTA (CBSE before 2019). Topic and idea tags, counts and notes are Lumi’s.