The electronvolt (eV) is a unit of energy in the International System of Units (SI) that is extensively utilized in particle physics and atomic physics. It represents the amount of kinetic energy gained by an electron accelerating through an electric potential difference of one volt. Because it is derived from fundamental electrical units, the electronvolt is the standard unit for measuring energy levels associated with subatomic particle interactions. Its use simplifies calculations involving high-energy processes, allowing for convenient quantification of energy in processes such as those observed when electrons are emitted, absorbed, or scattered by atoms.