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What holds conducting electrons from flying off into vacuum

  1. Apr 4, 2012 #1
    In a conductor suspended in an external electric field, in a vacuum, what holds the conducting electrons inside the conductor? Why don't they just fly off into space, under the influence of the field? If they are free enough to move between the atoms of the conductor, this means the force from the atomic nuclei etc. is not great enough to bind them to a specific location/atom. So why is it any different at the surface?
  2. jcsd
  3. Apr 4, 2012 #2
  4. Apr 4, 2012 #3


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    While in the simplest approximation these electrons are considered to be "free electrons", in reality, they aren't! They still see the periodic potential of the ions of the metal. So in essence, they are still bounded to the metal. This is why we have the "work function".

  5. Apr 4, 2012 #4


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    Yes as in any sort of electronic vacuum tube. say a TV picture tube

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