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Homework Help: Quantum Question and Binding Energy Question

  1. Sep 24, 2005 #1

    I have the following MC question and I do not understand it at all. Can you please help me with this.

    Determine which H atom transition (ninitial,nfinal) was responsible for the emission of a photon with a frequency of 6.17 x 1014 Hz.
    [RH = 2.18 x 10-18 J; h = 6.63 x 10-34 J s ]

    a. (2,3)
    b. (2,4)
    c. (5,2)
    d. (4,2)
    e. (3,2)

    Also, Im stuck with this question:
    A metal has a threshold wavelength, for the onset of the photoelectric effect, of 524 nm. What is the binding energy (in kJ/mol) of an electron to the metal surface?

    Any help would be much appricieated
  2. jcsd
  3. Sep 24, 2005 #2
  4. Sep 24, 2005 #3
    Thanks. For the first question though, how I do isolate to solve for the two n values? Im very confused about this
  5. Sep 24, 2005 #4


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    Homework Helper

    Look, it's multiple choice! An electron transition
    from n=2 to n=3 would require (absorb) Energy.
    So the photon is emitted in a transition to n = 2.
    Try the middle initial state; if that gives less energy
    than the photon took, then the electron must have
    started from higher up (ie, n=5)
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