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Homework Help: Magnetic moment of proton and electron of H-atom in ground state L=0

  1. Mar 7, 2012 #1
    1. The problem statement, all variables and given/known data

    Consider the Hydrogen atom in a magnetic field of 2T. If the atom is in its ground state (orbital angular momentum L=0):
    (a) Write down the magnetic moments of the proton and the spinning electron. [1]

    2. Relevant equations

    I am aware that the magnetic moment μ = (q/2m)L

    3. The attempt at a solution

    but because L=0 this means that μ=0 for both the proton and the electron, which doesn't seem to me to be a valid answer.

    Is this the correct way to be attacking this problem or am i missing something?

    Any help with pointing me in the right direction would be much appreciated.

    Last edited: Mar 7, 2012
  2. jcsd
  3. Mar 7, 2012 #2


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    I think it asks for the expectation value of the magnetic moment operator in the fundamental state (1s).
  4. Mar 8, 2012 #3
    Thanks for the help, but I've looked at it some more alongside my lecture notes and I think what they want is:

    [itex]\mu^{spin} = -2 \frac{e\hbar}{2m_{e}}m_{s} [/itex]

    for the electron, and for the proton:

    [itex]\mu = -2.79 \frac{e\hbar}{2m_{p}}m_{s} [/itex]

    Do you think that seems reasonable? Im gonna ask the lecturer tomorrow if it is the expectation value he wants or not.

    Thanks again for the feedback!
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