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Homework Help: Energy levels

  1. Sep 12, 2007 #1


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    Hi. This isnt so much a homework question, but more of a conceptual understanding question.

    Lets say an atom has a ground energy level defined at 0J.
    The energy levels are:

    E1 = 0 J
    E2 = 7.77*10^-19 J
    E3 = 10.66*10^-19 J
    E4 = 14.1*10^-19 J
    E5 = 16.6*10^-19 J

    Now, if an electron with over 16.6*10^-19 J of energy is shot into the atom, what are the possible energies of photons that can be emitted?

    I would have started by saying:

    7.77*10^-19 J
    10.66*10^-19 J
    14.1*10^-19 J
    16.6*10^-19 J

    my textbook seems to agree with me there. Now, i would also think that more energies are possible, because of electrons going from one energy level other than the ground state to another. So the following would also be possible:

    2.89*10^-19 J
    6.33*10^-19 J
    3.44*10^-19 J

    The book didnt explicitly say these arent correct, but it didnt really mention them, so im not sure if my understanding is correct or not.

    Any help is appreciated,
    Thanks in advance,
  2. jcsd
  3. Sep 12, 2007 #2
    Yeah. That is possible. Eventually, the electron does end up at the ground level. I think the total number of paths is n*(n-1)/2.
  4. Sep 12, 2007 #3


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    Alright, thanks for clearing that up :smile:
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