3.12 Properties of Photons

Explain the properties of an absorbed or emitted photon in relationship to an electronic transition in an atom or molecule.

• When a photon is absorbed (or emitted) by an atom or molecule, the energy of the species is increased (or decreased) by an amount equal to the energy of the photon.
• The wavelength of the electromagnetic wave is related to its frequency and the speed of light by the equation: EQN: c = λν. The energy of a photon is related to the frequency of the electromagnetic wave through Planck’s equation: EQN: E = ℎν.