Work function: Difference between revisions

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== Photoelectric work function ==

In [[photoelectric emission]], the electron gains the kinetic energy needed to escape from photons, such an electron is called a photoelectron and the emission is called the [[photoelectric effect]].

In the [[photoelectric effect]]the work function of a metal is the minimum energy required to cause the emission of an electron from it's surface. If a [[photon]]incidenton the metal has an energy greater than the work function then electrons in the metal can escape from the surface and [[photoelectric emission]]occurs. Any excess energy is given to the electron as kinetic energy.

Photoelectric work function:

&phi;=hf<sub>0<sub>,

where h is [[Planck's constant]] and f<sub>0<sub> is the criticalminimum (threshold) frequency required for photoelectric emission.

== Thermionic work function ==