Are these the official NEET questions on Structure of Atom?

Yes. They are the questions NTA set in each paper, in its wording. The solutions are written by BrainIt.

Structure of Atom NEET PYQs with Solutions (2020 to 2026) PDF

The questions come from NEET 2026, Re-NEET 2026 and NEET 2020. Each shows its answer and solution when you open it, so you can attempt it first. For what the chapter covers and how NEET tests it, see the Structure of Atom guide.

Practise on the CBT screen4 questions, 4 minutes, marked +4 / −1 Download PDF3 pages, 0.7 MB, with answers and solutions

NEET 2026 · the full paper

NEET 2026 · Q49
Match List I (Quantum Numbers, given as n and l) with List II (Orbital):
List I
List II
P) n = 2, l = 1
I) 3d
Q) n = 4, l = 0
II) 2p
R) n = 5, l = 3
III) 4s
S) n = 3, l = 2
IV) 5f
1. (1)
  P-IV, Q-II, R-III, S-I
2. (2)
  P-II, Q-III, R-I, S-IV
3. (3)
  P-II, Q-III, R-IV, S-I
4. (4)
  P-I, Q-II, R-III, S-IV
Answer and solution
Answer: (3)
The orbital is named by n and the subshell letter for l (l = 0,1,2,3 -> s,p,d,f). So n=2,l=1 is 2p (II); n=4,l=0 is 4s (III); n=5,l=3 is 5f (IV); n=3,l=2 is 3d (I). This gives P-II, Q-III, R-IV, S-I.
NEET 2026 · Q56
A bulb is rated at 150 watt, converting 8% energy into light. If energy of one photon is $4.42 \times 10^{-19}\ \text{J}$ , how many photons are emitted by the bulb per second?
1. (1)
  $2.71 \times 10^{19}$
2. (2)
  $4.06 \times 10^{19}$
3. (3)
  $27.2 \times 10^{19}$
4. (4)
  $1.35 \times 10^{19}$
Answer and solution
Answer: (1)
In one second the bulb consumes 150 J; only 8% becomes light, so light energy per second = $150 \times 0.08 = 12$ J. The number of photons n = (light energy)/(energy per photon) = $12 / (4.42 \times 10^{-19}) \approx 2.71 \times 10^{19}$ . The other options come from omitting the 8% factor or arithmetic errors.

List I	List II
P) n = 2, l = 1	I) 3d
Q) n = 4, l = 0	II) 2p
R) n = 5, l = 3	III) 4s
S) n = 3, l = 2	IV) 5f

Re-NEET 2026 · the full paper

Re-NEET 2026 · Q88
Consider the following schematic plots of orbital wavefunction ( $\psi_r$ ) against distance (r) from the nucleus.
The figure representing two radial nodes in the orbital is
1. (1)
  A
2. (2)
  B
3. (3)
  C
4. (4)
  D
Answer and solution
Answer: (3)
A radial node is a distance at which the wavefunction actually CHANGES SIGN, so on a $\psi_r$ versus r plot you simply count how many times the curve crosses the horizontal axis. Merely approaching zero asymptotically at large r does not count. The plot labelled C crosses the axis twice - once into negative values and once back up - so it has two radial nodes, matching an orbital with $n - l - 1 = 2$ such as 3s. NCERT Class 11, Structure of Atom (quantum mechanical model, nodes).

Why the other options are wrong:

- (1) shows a curve that decays without ever changing sign - zero radial nodes, as in 1s
- (2) crosses the axis only once, so it has a single radial node
- (4) crosses more often than twice, so its node count is higher than asked for

NEET 2020 · the full paper

NEET 2020 · Q110
The number of protons, neutrons and electrons in $^{175}_{71}$ Lu, respectively, are
1. (1)
  104, 71 and 71
2. (2)
  71, 71 and 104
3. (3)
  175, 104 and 71
4. (4)
  71, 104 and 71
Answer and solution
Answer: (4)
The atomic number (71) gives the number of protons and electrons, and the mass number (175) minus the atomic number gives the number of neutrons: 175 - 71 = 104. Chapter: Structure of Atom.

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Structure of Atom: NEET previous year questions

NEET 2026 · the full paper

Re-NEET 2026 · the full paper

NEET 2020 · the full paper

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