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Electron Configuration for Multivalent electrons.

  1. Sep 24, 2012 #1
    I am trying to draw electron configurations for multivalent electrons for Pb4+ and Pb2+.
    The work I have:
    (Xe)6s24f145d10 (PB2+)
    (Xe)6s04f145d10 (PB4+)

    the problem I'm having with multivalent structures is:
    I have no idea which electrons to remove when there is an ionic charge
    For instance, I don't know whether I should remove p orbital before s etc.

    Can someone explain the concept for electron configurations for atoms in d-block
  2. jcsd
  3. Sep 25, 2012 #2
    Is this for a class? I ask because there's a difference between the questions "What should I write down to get full credit" and "what is the right way to think about electrons in multi-electron atoms". Strictly speaking, this business of saying that "this electron is a 3p while this other one is a 4s" is wrong. You can't distinguish between electrons in that way, all you can say are things about the total multi-electron wavefunction.

    The "shell model" is based on patterns in the ionization potentials backed up by simplistic (Hartree-Fock) calculations that use the orbital approximation to try to give a clear model. If you want to make the most grounded argument, you'll have to look at what the ionization potential trends are for PB to see if they look like you're removing electrons from an "s-orbital" (within the trend you'll see two that are much more similar to each other than to the rest) or from a "p-orbital" (a trend where three look more similar followed by three that look similar to each other but slightly different from the previous three due to the electron pairing energy) etc. Doing it that way,you're still buying into the incorrect picture, but at least you're doing it based on firm experimental results.

    For more info, take a look at, say:
    Transition Metal Configurations and Limitations of the Orbital Approximation
    J. Chem. Ed. Volume 66 Number 6 June 1989 481
    Why Teach the Electron Configuration of the Elements as We Do?
    J. Chem. Ed. Volume 59 Number 9 September 1982 757
    Demystifying Introductory Chemistry Part 1: Electron Configurations from Experiment
    J. Chem. Ed. Volume 73 Number 7 July 1996 617
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