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Electrons always move?

  1. Jan 5, 2016 #1
    What keep electrons move? I read somewhere that in q physics the kinetic energy of an electron mean how much the wave cloud is compressed. If the electron is part of an atom its wave is wide a smeared but if delocalized then its wave is small and its position much more exact.
    But the electron can move/flow in a conductor. That's different moving? It has two kind of "moving"?
    And this classical moving also constant, e- always move as a wave and as a particle too?
     
  2. jcsd
  3. Jan 5, 2016 #2

    mfb

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    No. As an example, electrons in an atom do not move (with a few irrelevant exceptions). They have a kinetic energy, but this is nothing like motion in the classical sense.
    But if they move, without an external force they will keep moving - what would stop them?
    That does not make sense.
    Electrons are quantum objects, they are neither wave nor particle, although those descriptions can be useful sometimes.
     
  4. Jan 5, 2016 #3
    If we have a piece of metal, there is delocalized electrons on its surface. These electrons are moving or not? If moving then radiating EM energy and loose kinetic energy, finally stop moving. This would stop them.
    But if not move how can the changing magnetic field accelerate them? So called circular current induced but how? They are rest and cannot sense magnetic force.

    And there is the explanation (first answer) of electron wave compression and quantum kinetic energy what I said:
    https://van.physics.illinois.edu/qa/listing.php?id=1195
     
    Last edited: Jan 5, 2016
  5. Jan 5, 2016 #4

    mfb

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    Not only there.
    They can, it depends on the setup.
    Not if they move in a straight line, neglecting collisions with defects.
    The classical picture doesn't work well here. They have a momentum distribution, and the magnetic field acts on this distribution.
    That is not what you said. A more localized electron has a larger spread in momentum, it does not need to have a larger momentum. Turning that around makes it even worse, because a large momentum or even a large spread in momentum tells us nothing about the localization in space.
     
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