The discovery of the electron as a subatomic particle was a result of which experiment?

• A. Robert Millikan's oil drop experiment
• B. J.J. Thomson's cathode ray tube experiment
• C. Ernest Rutherford's gold foil experiment
• D. James Chadwick's neutron experiment

Answer: (B)

Verified step by step guidance

1. Understand that the question is about identifying the experiment that led to the discovery of the electron as a subatomic particle.
2. Recall the key experiments related to atomic structure: Millikan's oil drop experiment measured the charge of the electron, Rutherford's gold foil experiment discovered the nucleus, Chadwick's neutron experiment discovered the neutron, and Thomson's cathode ray tube experiment discovered the electron.
3. Focus on the purpose and outcome of J.J. Thomson's cathode ray tube experiment, which involved studying cathode rays and led to the identification of the electron as a negatively charged particle smaller than an atom.
4. Recognize that the other experiments, while important, did not discover the electron itself but rather measured its properties or discovered other subatomic particles.
5. Conclude that the discovery of the electron as a subatomic particle was a result of J.J. Thomson's cathode ray tube experiment.