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Homework Help: Photoelectric(excitation energy)

  1. Oct 3, 2008 #1
    1. The problem statement, all variables and given/known data

    The 1st excitation energy of hydrogen atom is 10.2 eV
    electron charge- mass ratio (e/m) = 1.7 x 10 11 kg -1

    Find speed of the slowest electron that can excite a hydrogen atom

    2. Relevant equations

    eV= 1/2 mv2 = hf = hc/lamda

    hf = work function energy + 1/2 mv 2

    3. The attempt at a solution

    Ans : 1.9 x 106ms-1
  2. jcsd
  3. Oct 3, 2008 #2
    ops delete this please.. just found it on another thread
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