Who discovered the electron?

Answer: A negatively charged particle is called an electron.

In 1897, J.J. Thomson. The electron was found through experimentation with a Crookes, or cathode ray, tube. He demonstrated the negative charge of cathode rays. Thomson found that the commonly accepted model of an atom could not account for negatively or positively charged particles.

The cathode ray tube studies of J.J. Thomson demonstrated that all atoms contain tiny, electron-like subatomic particles that are negatively charged.