Electron is an elementary particle that has a central role in chemistry and nuclear physics because of its interaction with other subatomic particles like protons. Together with neutron and proton, which are bound in a nucleus, it composes an atom. Electrons are directly tied to all of atom’s chemical properties and their exchange between two or more atoms is what causes chemical bonding.
Electron has negative elementary electric charge. They are bound to protons, which have positive elementary electric charge, by the electromagnetic force.
Electrons are leptons of the first generation. Being a lepton, it has ½ spin and is fermionic particle. Its mass is only 1/1863 of the proton or 9.109 × 10^−31 kg. Like all particles with mass, it is affected by gravity.
Electron is also affected by the weak force and it is emitted during beta decay where proton is transformed to neutron. The only fundamental force which has no effect on electrons is the strong force.
Its antiparticle is called positron and it has the same characteristics as electron, except it has positive elementary electric charge. When these two collide, they annihilate each other and energy is released.
Electrons have a central role in physical phenomena like electricity, magnetism and thermal conductivity. Electric current, for example, is the movement of electric charge via electrons. An electron also creates a magnetic field. Normally, electrons in a material have different movements and these individual magnetic fields cancel out, but if it happens that multiple electrons’ magnetic moments line up, the material can then create a net total magnetic field which we can observe in the form of magnetism.
When we heat a material like iron, we excite electrons around atomic nuclei and they move to higher orbits. While returning to their normal energy state and thus orbit, they emit excess energy via photons and we perceive that energy as light and heat as the iron shines.
Electron has properties of both particles and waves. It was discovered and identified as a particle in 1897 by J.J. Thomson. He received Nobel Prize in 1906 for this discovery. In 1937, his son George Paget Thomson won Nobel Prize for discovery of wave properties of the electron.