On this day (30 April) in 1897, Joseph J Thomson announced the discovery of the electron. It was the first time a subatomic particle had been discovered. This graphic takes a quick look at his discovery; for a more detailed explanation, check out this Institute of Physics article. For more on different models of the atom over the years, there’s this graphic highlighting key theories and models.
![04-30 – Discovery of the electron](https://i0.wp.com/www.compoundchem.com/wp-content/uploads/2018/04/04-30-–-Discovery-of-the-electron.png?resize=370%2C208&ssl=1)