Which physicist is credited with the discovery of the electron in 1897?

J. J. Thomson is credited with discovering the electron in 1897. Working at the Cavendish Laboratory in Cambridge, he demonstrated that cathode rays were streams of tiny, negatively charged particles present in atoms.

Thomson used improved vacuum tubes and tested how cathode rays responded to electric and magnetic fields. The same behavior appeared regardless of the gas or metal used in the apparatus, suggesting that the particles were universal components of matter rather than properties of one particular element. His measurements showed that the particles were far lighter than hydrogen atoms and had a very large charge-to-mass ratio.

Thomson initially called these particles “corpuscles.” The word electron had been suggested earlier by George Johnstone Stoney, and it eventually became the accepted name. Thomson’s work was a major blow to the idea that atoms were indivisible. In 1906 he received the Nobel Prize in Physics for his investigations of electrical conduction in gases.

The wording “discovery” has a historical nuance: scientists had studied cathode rays before Thomson, and Robert Millikan later measured the electron’s charge. Thomson is credited with identifying the particle itself.