# Planck's relation

## Description

Electrons can only gain and lose energy by jumping from one allowed orbit to another, absorbing or emitting electromagnetic radiation with a frequency “f” , determined by the energy difference of the levels.

The Planck–Einstein relation,also referred to as the Einstein relation, Planck’s energy–frequency relation, is a formula integral to quantum mechanics, and states that the energy of a photon (E) is proportional to its frequency (f).

(The frequency of the radiation emitted at an orbit of period T is the reciprocal of the classical orbit period).

## Variables

E_{2} | Initial electron energy (J) |

E_{1} | Final electron energy (J) |

h | Planck constant |

f | Frequency of the radiation (hertz) |