Results are out! Find what you Get quick advice or join the chat
Hey! Sign in to get help with your study questionsNew here? Join for free to post

electron configuration

Announcements Posted on
Don't forget to check out our results day hub. See you on the day for celebration and support, good luck! 22-06-2015
Will you get the grades you need for uni? Get prepared today and de-stress, sign up to email alerts for course places! 02-06-2015
  1. Offline

    ok so am trying to revise electron configuration...heres the question :
    Write the electronic configuration of V(3+) using the orbital method

    heres the answer :

    1s2 2s2 2p6 3s2 3p6 3d2

    my question is that shouldnt the 4s2 orbital be filled first because its lower in energy than the 3d orbital and since theres only 2 electrons left filling the 4s2 orbital would make it more stable???
  2. Offline

    This is indeed very confusing!

    The explanation is that the energies of the different orbitals are not actually constant, but depend on what other orbitals are filled. When both the 3d and 4s are empty, the 4s orbital is lower in energy, and so it fills up first. However once you add electrons to the 3d orbital the 4s orbital actually becomes higher in energy than the 3d. Hence the electrons are removed from the 4s orbital first.

    You might expect that once you had removed the electrons from the 4s orbital the ones in the 3d would move to the 4s (as it's now lower in energy). However this d->s transition is forbidden and so this doesn't happen.

    Hope this helps!


Submit reply


Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: May 5, 2012
New on TSR

Should there be more homework?

How much is too much?

Study resources
Article updates

Think you'll be in clearing or adjustment?

Hear direct from unis that want to talk to you

Get email alerts for university course places that match your subjects and grades. Just let us know what you're studying.

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.