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Structure of Atom CBSE Class 11 MCQ & Practice Questions

Practice Structure of Atom MCQs for CBSE Class 11 Chemistry with answers, explanations, chapter revision and related ChemNexa mock tests.

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Structure of Atom Revision Guide for CBSE Class 11 Chemistry

Structure of Atom is part of CBSE Class 11 Chemistry preparation. A strong revision plan should combine concept review with exam-style questions so that definitions, relationships, calculations and exceptions are recalled accurately.

Use the sample MCQs on this page to check understanding, then attempt the related ChemNexa tests for broader practice. When an answer is wrong, review the explanation and return to the underlying concept before attempting another set.

Important Topics

  • Core definitions and principles
  • Important equations or relationships
  • Common applications and examples
  • Frequently confused concepts
  • Exam-style multiple-choice questions
  • Error review and targeted revision

Revision Tip

Create a one-page summary of trends, structures, reactions, exceptions and key terminology for Structure of Atom, then test recall with mixed MCQs.

What to practise in Structure of Atom

Concept Revision

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Exam-style MCQs

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Performance Practice

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Top 20 Structure of Atom MCQs with Answers

These public questions are selected from the exact Structure of Atom chapter, screened for topic relevance and deduplicated so repeated versions of the same MCQ are not shown publicly. Use them for quick revision, then sign in to attempt the complete test experience with more questions, results and performance review.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

1. The charge-to-mass ratio of the electron was determined by:

  • A. Rutherford
  • B. J. J. Thomson
  • C. Chadwick
  • D. Millikan
Answer: B
Explanation: J. J. Thomson measured e/m for electrons using cathode rays.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

2. The charge on an electron was measured by:

  • A. Rutherford
  • B. Millikan
  • C. Bohr
  • D. Moseley
Answer: B
Explanation: Millikan's oil-drop experiment determined the electronic charge.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

3. The neutron was discovered by:

  • A. Goldstein
  • B. Chadwick
  • C. Bohr
  • D. Crookes
Answer: B
Explanation: James Chadwick discovered the neutron in 1932.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

4. Rutherford's α-scattering experiment established that:

  • A. Atom is indivisible
  • B. Positive charge is concentrated in a tiny nucleus
  • C. Electrons are stationary
  • D. Neutrons lie outside the nucleus
Answer: B
Explanation: Most α-particles passed through, while a few were strongly deflected, implying a tiny dense positive nucleus.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

5. The major limitation of Rutherford's model was that it could not explain:

  • A. Existence of nucleus
  • B. Atomic stability
  • C. Positive charge
  • D. Neutrons
Answer: B
Explanation: Classically, orbiting electrons should radiate energy and collapse into the nucleus.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

6. According to Bohr, angular momentum of an electron is quantised as:

  • A. mvr = nh
  • B. mvr = nh/2π
  • C. mvr = h/n
  • D. mvr = 2πnh
Answer: B
Explanation: Bohr proposed mvr = nh/2π.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

7. For a hydrogen-like species, the radius of nth orbit is proportional to:

  • A. n/Z
  • B. n²/Z
  • C. Z/n²
  • D. 1/nZ
Answer: B
Explanation: rₙ ∝ n²/Z.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

8. The energy of an electron in the nth orbit of hydrogen is proportional to:

  • A. −1/n
  • B. −1/n²
  • C. n²
  • D. 1/n³
Answer: B
Explanation: For hydrogen, Eₙ = −13.6/n² eV.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

9. Which transition in hydrogen emits the highest-energy photon?

  • A. n=2→1
  • B. n=3→2
  • C. n=4→3
  • D. n=5→4
Answer: A
Explanation: The n=2→1 transition has the largest energy difference among these.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

10. The Lyman series lies in the:

  • A. Visible region
  • B. Infrared region
  • C. Ultraviolet region
  • D. Microwave region
Answer: C
Explanation: Lyman transitions end at n=1 and occur in the ultraviolet.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

11. The Balmer series lies mainly in the:

  • A. Visible region
  • B. Ultraviolet region
  • C. X-ray region
  • D. Radio region
Answer: A
Explanation: Balmer transitions terminate at n=2 and several lines are visible.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

12. de Broglie wavelength is given by:

  • A. λ = hν
  • B. λ = h/p
  • C. λ = p/h
  • D. λ = hc/E²
Answer: B
Explanation: Matter wavelength is λ = h/p.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

13. If the momentum of a particle doubles, its de Broglie wavelength becomes:

  • A. Double
  • B. Half
  • C. Four times
  • D. Unchanged
Answer: B
Explanation: Since λ = h/p, doubling p halves λ.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

14. Heisenberg uncertainty principle relates uncertainty in:

  • A. Mass and charge
  • B. Position and momentum
  • C. Energy and mass
  • D. Velocity and charge
Answer: B
Explanation: Δx·Δp ≥ h/4π.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

15. The maximum number of electrons in a shell with principal quantum number n is:

  • A. n²
  • B. 2n
  • C. 2n²
  • D. n³
Answer: C
Explanation: A shell can hold a maximum of 2n² electrons.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

16. The number of orbitals in a shell with principal quantum number n is:

  • A. n
  • B. 2n
  • C. n²
  • D. 2n²
Answer: C
Explanation: Total orbitals in a shell = n².

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

17. For an orbital, the azimuthal quantum number l determines its:

  • A. Size
  • B. Shape
  • C. Orientation
  • D. Spin
Answer: B
Explanation: The l quantum number identifies subshell type and orbital shape.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

18. The magnetic quantum number mₗ determines orbital:

  • A. Energy only
  • B. Orientation
  • C. Spin
  • D. Size
Answer: B
Explanation: mₗ specifies orientation in space.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

19. For a p-subshell, the possible values of mₗ are:

  • A. 0 only
  • B. −1, 0, +1
  • C. −2 to +2
  • D. ±1/2
Answer: B
Explanation: For l=1, mₗ = −1, 0, +1.

CBSE Class 11 Chemistry · Structure of Atom · Very Very Hard

20. How many orbitals are present in a d-subshell?

  • A. 3
  • B. 5
  • C. 7
  • D. 10
Answer: B
Explanation: For l=2, mₗ has five values, so five orbitals exist.

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Structure of Atom Practice Tests

Structure of Atom Frequently Asked Questions

How should I prepare Structure of Atom for CBSE Class 11 Chemistry?

Revise the core concepts first, make a short list of important relationships or exceptions, and then solve chapter-focused MCQs while reviewing every error.

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What should I do after getting an MCQ wrong?

Identify whether the mistake came from a concept gap, calculation, unit, sign, wording or memory error, review that point, and then attempt a similar question again.

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