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Homework Help: Calculating the energy level and radius for a helium atom

  1. Jul 22, 2008 #1
    1. The problem statement, all variables and given/known data

    Calculate the energy and radius for each of the five lowest (n = 1,2,3,4,5) electron orbits in a Helium atom with only one electron. Enter the energy as a positive value in units of "eV" and the radius in units of "nm". Hint: The Helium nucleus has 2 protons so Z = 2 and the ground state energy of Helium will be E0 = k(Ze)2/2r0.

    2. Relevant equations

    E = (E0/n2)*Z2
    E0= 13.6 eV
    3. The attempt at a solution

    I got the correct answers for n = 1-2 and 4-5, but I cannot get the right answer for n=3. could you check my work?

    The answers I got were E = 6.044 eV and r = .238 nm
  2. jcsd
  3. Jul 23, 2008 #2


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    Homework Helper
    Gold Member

    I am getting the same numbers you are ttk3. The process for finding the answer for n=3 is the same as it is for the other four you got correct, so I don't see how you could get only n=3 incorrect.

    Are you sure there isn't some error or typo in wherever you are getting the correct answer from?
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