What holds conducting electrons from flying off into vacuum

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Discussion Overview

The discussion centers around the question of what prevents conducting electrons in a conductor from escaping into a vacuum when subjected to an external electric field. It explores the nature of electron behavior in conductors, particularly at the surface, and the implications of electric fields on electron movement.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions why conducting electrons do not escape into space under the influence of an external electric field, given their mobility within the conductor.
  • Another participant suggests that the energy required for electrons to escape is insufficient, drawing an analogy to the inability to jump off Earth into the upper atmosphere.
  • A different viewpoint emphasizes that while electrons are often treated as "free," they are still influenced by the periodic potential of the metal's ions, which contributes to their confinement within the conductor.
  • References to the concept of "work function" are made to explain the energy barrier that prevents electrons from leaving the conductor.
  • There are mentions of the possibility of electrons being emitted under strong electric fields, as seen in electronic vacuum tubes.

Areas of Agreement / Disagreement

Participants express differing views on the mechanisms that prevent electrons from escaping, with some focusing on energy considerations and others on the influence of atomic potentials. The discussion remains unresolved with multiple competing perspectives presented.

Contextual Notes

Some assumptions regarding electron behavior and energy levels are not fully explored, and the discussion does not resolve the complexities of the work function or the conditions under which electrons may escape.

Who May Find This Useful

This discussion may be of interest to those studying electrical conduction, solid-state physics, or anyone curious about the behavior of electrons in conductive materials under external fields.

bob900
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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?
 
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bob900 said:
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?

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".

Zz.
 
Naty1 said:
....
Try here too:

http://en.wikipedia.org/wiki/Valence_band

With a strong enough electric field, you can send electrons off...

If you want more detail, try ELECTRON BINDING ENERGY


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

Dave
 

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