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Discuss the evidence from the periodic table

  1. Dec 4, 2011 #1
    1. The problem statement, all variables and given/known data

    Discuss the evidence from the periodic table of the need for a fourth quantum number. How would the properties of He differ if there were only three quantum numbers, n, l, and m?

    2. Relevant equations



    3. The attempt at a solution

    The Pauli Exclusion Principle dictates that no two electrons can occupy exactly the same orbital configuration. If there was no fourth quantum number, atoms with the same n,l, and m, would be smaller.
     
  2. jcsd
  3. Dec 5, 2011 #2

    BruceW

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    Re: spin

    I agree with the first sentence. But I don't understand what you mean by the second sentence.
     
  4. Dec 5, 2011 #3
    Re: spin

    It was a hint someone else gave me, but it doesn't make sense to me either.
     
  5. Dec 5, 2011 #4
    Re: spin

    could you enumerate the possible (n, l, m) combinations in terms of rising energy?
     
  6. Dec 5, 2011 #5

    BruceW

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    Re: spin

    hmm. I think we should move on from that then. Your first sentence is the key to the answer.

    To answer how the properties of the helium atom changes, first think how many electrons are in a helium atom. Then from here, how would you determine the properties of the atom?
     
  7. Dec 5, 2011 #6

    dextercioby

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    Re: spin

    If there was no spin, there wouldn't be a periodic table...
     
  8. Dec 5, 2011 #7
    Re: spin

    for what particles does the Pauli Exclusion Principle hold?
     
  9. Dec 5, 2011 #8
    Re: spin

    Fermions, which include electrons, the relevant particles here.
     
  10. Dec 5, 2011 #9
    Re: spin

    yes, but saying something is a fermion is merely a tautology, because the Fermi-Dirac statistics is a consequence of the Pauli Exclusion Principle. There is another intrinsic characteristic of a particle which determines what kind of statistic it obeys.
     
  11. Dec 5, 2011 #10
    Re: spin

    ...particles that can only have antisymmetric total wave functions?
     
  12. Dec 5, 2011 #11
    Re: spin

    you are saying the same thing over and over. There is one crucial piece of evidence.
     
  13. Dec 5, 2011 #12
    Re: spin

    particles that are identical to eachother?
     
  14. Dec 5, 2011 #13
    Re: spin

    photons are identical to each other as well. Do they obey the Pauli Exclusion Principle?
     
  15. Dec 5, 2011 #14
    Re: spin

    Does it have something to do with the electrons' bound state and their overlapping wavefunctions?

    A appreciate your patience and won't be offended if you decide to abandon the thread.
     
  16. Dec 5, 2011 #15
    Re: spin

    Actually, I don't want to guide you in a wrong direction. I think your professor wants you to pursue a line of reasoning that I started with my first reply in this thread. However, while looking at reply #6, it occured to me that the division of particles in fermions and bosons has to do with one fundamental property that they posses. If you are a chemist, or in lower undergraduate course, you might not be aware of this connection, so I appologize for derailing this thread.
     
  17. Dec 5, 2011 #16

    BruceW

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    Re: spin

    Dickfore - I agree with your last post. You got a bit carried away :)

    awat - start with how many electrons are in a helium atom.
     
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