"The electron is a subatomic particle, (denoted by the symbol
e−
or
β−
), whose electric charge is negative one elementary charge.[9] Electrons belong to the first generation of the lepton particle family,[10] and are generally thought to be elementary particles because they have no known components or substructure.[1] The electron has a mass that is approximately 1/1836 that of the proton."
https://en.m.wikipedia.org/wiki/Electron