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Homework Help: Photon/Electron absorbtion in atoms

  1. Nov 7, 2005 #1
    Hi guys,
    I have this question I can do the first part but not the second, any help would be appreciated. Thanks in advance! :cool: o:)
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    http://img381.imageshack.us/img381/6778/ocau9rj.th.jpg [Broken]
    Question 1
    A photon with energy of 6.7eV is fired at the mercury, describe what would happen?
    Answer
    Photon would be absorbed and electron would jump to n=3 (the second excited state) and almost instantaneously electron will return back to the ground state whilst simultaneously emitting a photon (emission spectrum)
    Question 2
    An electron with 6eV is fired at the mercury, describe what would happen?
    Answer
    I have no idea, please help!
     
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Nov 7, 2005 #2

    Gokul43201

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    1. Correct.

    2. Let's try and guess something....does the electron just pass right through, or does it collide with something ? If it does, what could this something be ? And if there was a collision, what could happen to the energy of this electron (6eV), after the collision ?
     
  4. Nov 7, 2005 #3
    I was thinking that the 6eV electron would impart some of its energy onto the other electron (if it hits it) which would excite the electron to n=2 and the rest of the energy would be the Kinetic energy of the incident electron. I.e. compton scattering?
     
  5. Nov 11, 2005 #4

    Gokul43201

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    That's correct. It is a similar process to Compton scattering.
     
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