Concept:The electron was discovered by the scientist who showed that cathode rays consist of tiny negatively charged particles.
Explanation:In 1897, J.J. Thomson (written as Thompson in option C) performed experiments using a cathode ray tube.
He noticed that the rays were deflected by electric and magnetic fields.
This meant the rays were made of small, negatively charged particles.
He named these particles electrons.
This discovery proved that atoms are not indivisible and contain smaller parts.
Dalton, Chadwick, and Bohr contributed to atomic theory, but none of them discovered the electron.
Therefore, the correct option is C.
Answer:C. J.J. Thompson