Photon Definition

Photon Definition: A photon is a discrete packet of energy associated with electromagnetic radiation (light). A photon has energy E which is proportional to the frequency ÃŽ ½ of the radiation: E hÃŽ ½, where h is Plancks constant. Also Known As: quantum, quanta (plural) Characteristics Photons are unique in that they have characteristics of both particles and waves at the same time. For students, it remains unclear as to whether a photon is a particle that travels in a wave pattern or a wave broken up into particles. Most scientists simply accept the photon as a unique packet of energy that has characteristics of both waves and particles. Properties of a Photon Behaves like a particle and a wave, simultaneouslyMoves at a constant  velocity,  c   2.9979 x 108  m/s (i.e. the speed of light), in empty spaceHas zero mass and rest energyCarries energy and momentum, which are also related to the frequency (nu)  and wavelength  (lamdba)  of the electromagnetic wave, as expressed by the equation  E  Ã‚  h nu  and  p  Ã‚  h  /  lambda.Can be destroyed/created when radiation is absorbed/emitted.Can have particle-like interactions (i.e. collisions) with electrons and other particles, such as in the  Compton effect  in which particles of light collide with atoms, causing the release of electrons.