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Homework Help: Broglie Wavelength

  1. Dec 11, 2011 #1
    1. The problem statement, all variables and given/known data

    An electron has a de Broglie wavelength equal to the diameter of a hydrogen atom in its ground state.
    What is the kinetic energy of the electron?

    How does this energy compare with the ground-state energy of the hydrogen atom?
    2. Relevant equations

    λ = h /mv
    diameter = 2 x bohr radius = 1.06e-10 m

    3. The attempt at a solution

    1.06e-10 = 6.63e-34/1.67e-27v
    v = 3.75e3 m/s
    .5(1.67e-27)(3.75e3)^2 = 1.17e-20 J = .0732 eV
    Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully.
  2. jcsd
  3. Dec 11, 2011 #2


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    Staff Emeritus
    Science Advisor
    Gold Member

    Well, your electron mass doesn't look right at all. I suspect that you used the value for the proton mass rather than the electron mass. They're different by a factor of more than 1000.
  4. Dec 11, 2011 #3
    hah that was it. Thanks
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