1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Wavelength in an electron transition

  1. May 4, 2009 #1
    1. Is a 4p -> 4s transition allowed in sodium? If so, what is the wavelength? If not, why not? (Z = 11 for sodium)



    2. [tex]\Delta[/tex]l = |l2 - l1| = 1
    That is for the first question, in which case it is allowed, hence |0-1| = |-1| = 1, and meets the requirements for the equation.

    The second part is what I don't understand because I used these equations:
    [tex]E_{n}[/tex] = [tex]\frac{-13.60}{n^{2}}[/tex]eV
    n = 1, 2, 3, ...


    Next I used:
    [tex]\Delta[/tex]E[tex]_{atom}[/tex] = E[tex]_{1}[/tex] - E[tex]_{2}[/tex] = 0

    Meaning, I get zero for this because of the repeating n = 4, then 4[tex]^{2}[/tex] which = 16 and therefore I have an issue here I do not know how to solve after pondering.

    The third equation I must use is:
    [tex]\lambda[/tex] = 1240 eV nm / [tex]\Delta[/tex]E

    But I am not there yet....


    3. As you can see my attempt is either erroneous or there is some sort of lone energy I am not aware of, by the way, the answer to this is:

    Yes; 2.21 [tex]\mu[/tex]m

    Thank you.
     
  2. jcsd
  3. May 4, 2009 #2
    Ummm... Are you sure it is 4p to 4s? Double check what is written.
     
  4. May 4, 2009 #3
    I did, three times...I guess I will just have to lose points for this.
     
  5. May 4, 2009 #4
    Is there a table in your book of the orbital dependence of the energy in sodium?
     
  6. May 4, 2009 #5
    Here is an equation that uses different effective nuclear charges depending on the orbital quantum number:

    http://physics.wm.edu/~inovikova/phys251/manual/naspec.pdf [Broken]
     
    Last edited by a moderator: May 4, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Wavelength in an electron transition
  1. Electron Transitions (Replies: 2)

  2. Electronic Transitions (Replies: 2)

Loading...