In 1895, British physicist J.J. Thomson identified the electron as one of the fundamental particles from which atomic matter is composed. Negatively charged electrons are attracted to positively charged protons, and this bonding of electrons to protons is responsible for the characteristics (structure and chemistry) of atomic matter.

The rest mass of an electron is only 9.10939 × 10^-31 kg, about 2,000 times less than the lightest element, hydrogen. Therefore, although the electron is one of the most common constituents of the Universe, it accounts for only a tiny fraction of the Universe’s mass.

The charge of the electron is 1.60217733 × 10^-27 C (where C is a Coulomb).

The anti-particle of the electron is the positron, which has the same mass but opposite charge.

Electrons, along with muons and neutrinos are members of a family of sub-atomic particles known as leptons, which do not experience the strong-nuclear force.