The [[photoelectric effect]] work function is the minimum energy requiredthat tomust causebe thegiven emission ofto an electron to liberate it from the surface of a particular metal's surface. IfIn the a [[photonphotoelectric effect]] isincidentif ona the metal and[[photon]] haswith an energy greater than the work function thenis electronsincident inon thea metal can escape from the surface and [[photoelectric emission]] occurs. Any excess energy is given to the electron as kinetic energy.
