Which scientist is credited with discovering the electron?

• A. Niels Bohr
• B. Ernest Rutherford
• C. J.J. Thomson
• D. Robert Millikan

Answer: (C)

Verified step by step guidance

1. Understand that this question is about the historical discovery of the electron, a fundamental particle in chemistry and physics.
2. Recall that the electron was discovered through experiments involving cathode rays, which are streams of electrons observed in vacuum tubes.
3. Identify the scientist who conducted these cathode ray tube experiments and concluded the existence of the electron as a negatively charged particle.
4. Recognize that J.J. Thomson is credited with this discovery in 1897, based on his measurements of the charge-to-mass ratio of the electron.
5. Note that other scientists listed, such as Niels Bohr and Ernest Rutherford, contributed to atomic theory but did not discover the electron itself.