29 dic 1855 anni - J.J. Thomson
Descrizione:
Development of the Atomic Theory. In 1897, J.J. Thomson discovered the electron by experimenting with a Crookes, or cathode ray, tube. He demonstrated that cathode rays were negatively charged.Aggiunto al nastro di tempo:
Data:
29 dic 1855 anni
Adesso
~ 169 years ago