Who discovered the electron?

The electron was discovered in 1897 by British physicist Joseph John Thomson. He conducted experiments with cathode rays and found they contained negatively charged atomic particles with very little mass. For his work, Thomson was awarded the Nobel Prize in Physics in 1906.

Thomson's discovery was the first experimental evidence that proved that atoms could be divided into smaller units. Prior to his discovery, it was widely believed that the atom was the basic unit of matter. Some scientists had theorized the existence of smaller subatomic particles, but believed they would be similar in size to a hydrogen atom. Thomson was the first to propose the radical notion that these particles could be over 1,000 times smaller than atoms. He initially referred to these particles as "corpuscles," but this term was later changed to "electrons."