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Homework Help: Spectral lines and energy levels

  1. Apr 13, 2014 #1
    1. The problem statement, all variables and given/known data
    In the spectrum depicted bellow (see added picture) are spectral lines which resulted from emissions of a photon due to an electron decaying from a higher to a lower orbital in a Hydrogen-like atom (meaning- only one electron. No details about the nucleus)
    All lines in the given spectrum are a result of an electron decaying for an excited state to the first excited state. The wavelength of line C is 48.214nm, Calculate the energy of a photon co-responding to line D.

    2. Relevant equations

    E(ph)= hv
    Reidberg's equation (too complicated to type in)

    3. The attempt at a solution

    Our presentation didn't include any similar example, so i'm at a loss about how to approach this. Been staring at the page for a better part of the day.
    Any help would be much appreciated

    Attached Files:

  2. jcsd
  3. Apr 13, 2014 #2
    The Rydberg formula for hydrogen-like atoms is:
    Since the graph constitutes the entire spectrum for any [itex]n_i\rightarrow2[/itex] transition with [itex]n_i>2[/itex], where [itex]n_f=2[/itex] for any transition (since [itex]n=2[/itex] for the first excited state).
    Notice that A corresponds to transition [itex]3\rightarrow2[/itex], B corresponds to [itex]4\rightarrow2[/itex] and so on, hence you can figure out which transitions correspond to lines C and D respectively.
  4. Apr 19, 2014 #3
    ok, this clarified some things up, especially explaining the transitions.

    thanks, i got it. Also managed to understand things properly along the way.
    Last edited: Apr 19, 2014
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