👉 The electronvolt (eV) is a unit of energy that is equivalent to the amount of energy required to emit an electron from a single proton. It was first defined by physicist Erwin Schrödinger in 1926 as the energy required to create or destroy a single proton, and it has since been used to measure the energy of electrons in various elements. The electronvolt is one of the two fundamental units of energy in chemistry, along with the kilojoule (
