The Compton wavelength is a quantum mechanical property of a particle. The Compton wavelength of a particle is equal to the wavelength of a photon whose energy is the same as the mass of that particle (see mass–energy equivalence). It was introduced by Arthur Compton in his explanation of the scattering of photons by electrons (a process known as Compton scattering). The standard Compton wavelength, λ, of a particle is given by, while its frequency is given by,