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Structure of Atom WBCHSE Class 11 MCQ & Practice Questions

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

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Structure of Atom Revision Guide for WBCHSE Class 11 Chemistry

Structure of Atom is part of WBCHSE 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.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

1. The electron was discovered through experiments involving:

  • A. Alpha particles
  • B. Neutrons
  • C. Cathode rays
  • D. Canal rays
Answer: C
Explanation: Cathode-ray experiments established the existence of negatively charged electrons.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

2. J. J. Thomson measured the:

  • A. Planck constant
  • B. Charge-to-mass ratio of electron
  • C. Charge of proton
  • D. Mass of neutron
Answer: B
Explanation: Thomson determined e/m for cathode-ray particles.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

3. The charge of the electron was measured accurately by:

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

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

4. The neutron was discovered by:

  • A. J. J. Thomson
  • B. Rutherford
  • C. Bohr
  • D. James Chadwick
Answer: D
Explanation: Chadwick identified the neutron in 1932.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

5. Rutherford's alpha-particle scattering experiment showed that most of the atom is:

  • A. Filled with neutrons
  • B. A solid sphere
  • C. Empty space
  • D. Uniform positive charge
Answer: C
Explanation: Most alpha particles passed through with little deflection.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

6. Rutherford concluded that most positive charge is concentrated in the:

  • A. Entire atom uniformly
  • B. Nucleus
  • C. Electron cloud
  • D. Valence shell
Answer: B
Explanation: Large-angle scattering required a tiny dense positively charged nucleus.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

7. The major problem with Rutherford's model was that it could not explain:

  • A. Atomic stability
  • B. Existence of protons
  • C. Neutrality of atoms
  • D. Mass number
Answer: A
Explanation: Classically orbiting electrons should radiate energy and collapse into the nucleus.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

8. Planck proposed that energy is exchanged in packets called:

  • A. Orbitals
  • B. Nuclei
  • C. Isotopes
  • D. Quanta
Answer: D
Explanation: Planck introduced discrete energy packets or quanta.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

9. The energy of one photon is:

  • A. ν/h
  • B. hcν
  • C. hν
  • D. h/ν
Answer: C
Explanation: Photon energy is directly proportional to frequency: E=hν.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

10. For electromagnetic radiation in vacuum:

  • A. c=hν
  • B. c=νλ
  • C. c=ν/λ
  • D. c=λ/ν
Answer: B
Explanation: Speed of light equals frequency times wavelength.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

11. If wavelength decreases, frequency:

  • A. Increases
  • B. Decreases
  • C. Remains constant
  • D. Becomes zero
Answer: A
Explanation: Since c is constant, frequency varies inversely with wavelength.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

12. Hydrogen gives a line spectrum because electronic energies are:

  • A. Continuous
  • B. Zero
  • C. Independent of quantum number
  • D. Quantised
Answer: D
Explanation: Discrete energy levels yield discrete photon energies.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

13. The Lyman series corresponds to transitions ending at:

  • A. n=3
  • B. n=4
  • C. n=1
  • D. n=2
Answer: C
Explanation: Lyman-series transitions terminate at the ground level n=1.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

14. The Balmer series corresponds to transitions ending at:

  • A. n=4
  • B. n=2
  • C. n=1
  • D. n=3
Answer: B
Explanation: Balmer lines arise from transitions to n=2.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

15. The Paschen series corresponds to transitions ending at:

  • A. n=3
  • B. n=1
  • C. n=2
  • D. n=4
Answer: A
Explanation: Paschen-series transitions terminate at n=3.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

16. The Balmer series lies mainly in the:

  • A. Ultraviolet region
  • B. X-ray region
  • C. Microwave region
  • D. Visible region
Answer: D
Explanation: Several Balmer lines occur in the visible region.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

17. The Lyman series lies mainly in the:

  • A. Infrared region
  • B. Radio region
  • C. Ultraviolet region
  • D. Visible region
Answer: C
Explanation: Transitions to n=1 release high-energy ultraviolet photons.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

18. According to Bohr, electrons in stationary orbits:

  • A. Must spiral into nucleus
  • B. Do not continuously radiate energy
  • C. Continuously lose energy
  • D. Have arbitrary angular momentum
Answer: B
Explanation: Bohr postulated stable non-radiating stationary states.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

19. Bohr's angular momentum condition is:

  • A. mvr=nh/2π
  • B. mvr=h/n
  • C. mvr=2πnh
  • D. mvr=0
Answer: A
Explanation: Allowed orbital angular momenta are integral multiples of h/2π.

WBCHSE Class 11 Chemistry · Structure of Atom · Very Hard

20. For a hydrogen-like ion, radius of nth orbit is proportional to:

  • A. Z/n²
  • B. n/Z²
  • C. 1/nZ
  • D. n²/Z
Answer: D
Explanation: Bohr radius scales as n²/Z.

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Structure of Atom Practice Tests

Structure of Atom Frequently Asked Questions

How should I prepare Structure of Atom for WBCHSE 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?

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