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Homework Help: Principal Quantum number by size?

  1. Jul 19, 2010 #1
    1. The problem statement, all variables and given/known data
    What is the value of the principal quantum number for a hydrogen atom to have a size of one micron?


    2. Relevant equations
    r=(5.3x10-11)(n2)
    r=1x10-6/2=5x10-7


    3. The attempt at a solution

    5x10-7=(5.3x10-11)(n2)

    97.1 = n

    How is this possible? lol Maybe it's more complicated then I'm thinking.
     
  2. jcsd
  3. Jul 19, 2010 #2

    Redbelly98

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    Just use the nearest integer value.
     
  4. Jul 19, 2010 #3
    So I'm right? The answer is just 97? I thought the principal quantum numbers (n) only go up to like 5 or 6 or something like that though.
     
  5. Jul 19, 2010 #4

    Redbelly98

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    Yes, you're right. n can go up to infinity in theory. In practice, an atom with such a high n would eventually collide with another atom or perhaps a container wall, and completely lose the electron.
     
  6. Jul 20, 2010 #5
    Alrighty, thank you very much :)
     
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