1. Limited time only! Sign up for a free 30min personal 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!


  1. Apr 16, 2015 #1
    1. The problem statement, all variables and given/known data
    While reading d and f block elements from my book I got this line:
    "The irregular trend in the first ionization enthalpy of the 3d metals can be accounted for considering that the removal of one electron alters the relative energies of 4s and 3d orbitals. So the unipositive ions have dn configurations with no 4s electrons. There is thus a REORGANISATION ENERGY accompanying ionisation with some gains in exchange energy as the number of electrons increases and from the transference of s electrons into d orbitals. "

    2. Relevant equations

    3. The attempt at a solution
    First of all, if any unipositive element has dn configuration then why would it have no electrons in its s orbital? (As the second line says)
    And the third line, I didn't get anything of it...
  2. jcsd
  3. Apr 17, 2015 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    The context suggests that, prior to ionization, there was only one 4s electron.
  4. Apr 17, 2015 #3
    I think you're saying it on behalf of:
    Am I correct?
    Though now I understand the second line, but third one is still a mile away from my understanding.
  5. Apr 17, 2015 #4

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    Well I got it off the first sentence.

    Take a look at the order of states across the 3 and 4 shells.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Discussions: What is this EXCHANGE ENERGY?
  1. Ionic exchange (Replies: 1)