Explanation by photon theory The result cant be explained by classical theory An electron is ejected from the metal by a collision (inelastic)with a single photon photon electron(be absorbed energy Minimum energy to get out: work function Wo hf=e +w k max Photoelectric equationExplanation by photon theory 11 The result can’t be explained by classical theory An electron is ejected from the metal by a collision (inelastic) with a single photon. photon energy electron (be absorbed) Minimum energy to get out: work function W0 k max 0 hf  E W Photoelectric equation