SDN members see fewer ads and full resolution images. Join our non-profit community!

Gen Chem Question

Discussion in 'MCAT Study Question Q&A' started by Farcus, Jun 20, 2008.

  1. Farcus

    Farcus 10+ Year Member

    Nov 28, 2007
    My Bed
    292. Find the element possessing the set of quantum numbers [5, l, -l, +l/2] for its last electron.
    1) 31Ga 2) 47Ag 3) 50Sn 4) 81Tl 5) none of these
    ANS: 5

    How is this problem correct?

    Ok primary quan number is 5 so 2:thumbdown:^2=50 which make sense to be 3 right? since SN has 50 protons. and also 1 is the L then it means it has S and P orbitals that SN does have and -1 would mean Px. How is it None of the above?
  2. SDN Members don't see this ad. About the ads.
  3. BerkReviewTeach

    BerkReviewTeach Company Rep & Bad Singer Exhibitor 10+ Year Member

    May 25, 2007
    SDN Exhibitor
    Five answer choices? You might want to reconsider the materials. While it's a good question, five answer choices is not realistic, so the materials may not be realistic.

    n = 5 thus fifth shell
    l = 1 thus p-orbital
    ml = -1 so it's a px orbital
    ms = +1/2, so it's spin up

    This means that we need to look at the first element in the fifth row of the p-block to find the element with those quantum numbers for the last electron. That happens to be In, element 49.
  4. Farcus

    Farcus 10+ Year Member

    Nov 28, 2007
    My Bed

    but had the problem been [5, l, -l, + and - l/2]

    it would of been SN right? since -1 mean Px which is either In or Sn but since there are two electrons now then it'll be SN right?

    I know its not realistic I just found this online, I needed to brush up on my Gen Chem.

Share This Page