Class 12 Physics Dual Nature Radiation Matter Electron Emission

Electron Emission:

  • The process of emission of electrons from the metal surface when a certain amount of energy is absorbed by the metal, is called electron emission
  • There are free electrons on the metal surface, present in the outermost (valence) shell that are loosely bound to the nucleus
  • These electrons are emitted when a certain minimum amount of external energy is provided to the metal surface. This least value of energy is called work function of metal (denoted by Φ0)
  • The unit of Φ0 is electron volt(eV). 1eV is defined as the energy needed to accelerate an electron through the potential difference of 1volt(V).
  • Work function of a material depends mainly on the nature of metal, and electronic configuration of metal (meaning the number of valence shell electrons, lesser the number, lesser the work function)

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