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Homework Help: Photon Absorption

  1. May 30, 2008 #1
    Quick question: when an electron absorbs a photon with MORE THAN enough energy to jump one energy level but not two, what happens to the extra energy the electron doesn't absorb?

  2. jcsd
  3. May 30, 2008 #2


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    If there's no state for it to jump to by absorbing the whole photon, it can't absorb the photon.
  4. May 30, 2008 #3
    The probability, or cross sections for photon absorption for bond levels in atoms are extremely peaked at the frequency of the transition, [tex] h\nu = E_u - E_l [/tex], pretty much like delta functions. Well, they're actually Lorenzian profiles, but the width is extremely small, ~[tex]10^{-4} \AA [/tex] for most transitions. If the photon doesn't have essentially the same energy as the energy difference of the levels, it won't get absorbed.
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