Last revised by Francesco Sciacca on 25 Oct 2023

The electron is a subatomic particle that has negligible mass (9.109 x 10-31 kg) and is negatively charged (-1.6 x 10-19 Coulombs). The properties of x-rays and their interaction with matter concern the orbiting electrons within the atom.

In classical physics the electrons orbit the central positively charged nucleus in shells, the outermost one of which is termed the valence shell.

History and etymology

It was J. J. Thomson, English physicist (Nobel Prize, 1906) who discovered the electron in 1897.

ADVERTISEMENT: Supporters see fewer/no ads