Wednesday, November 9, 2011

Trimester One Exam Review - Question 26 and 27 (HUZZAH!)

Electron Configurations

S2- = [Ne] 3s2 3p6
Pb = [Xe] 6s2 4f14 5d10 6p2
Au = [Xe] 6s1 4f14 5d10
W = [Xe] 6s1 4f14 5d^5
P = [Ne] 3s2 3p3
Ba2+ = [Kr] 5s2 4d10 5p6

Orbital Diagrams

What generally happens to atomic mass from K to Kr? How do you rationalize what happens to atomic mass between Co, Ni, and Cu?
      a) The amu increases. 
      b) It increases because the most abundant cobalt isotope weighs less than the most abundant copper isotope. It decreases with nickel because it has a light weight isotope that is very abundant.

Fellow Readers, enjoy!
Cyrus, please don't  >:(


  1. Well done, Cara, I am very impressed. I am sure you will be very well prepared for the midterm. But as a fellow chemist, I feel it is my duty to point out four flaws, some more important than others. First, in the picture, you wrote S2- in pink and its orbital filling diagram in coral. You probably realized that the pink pen was too thick to draw arrows with, but nevertheless, this was the first thing you wrote so it would have been easy to start over. I suppose I am just being picky though. Second, how come some of the orbital diagrams have an "=" signs while others do not? Consistency is key! Now to the real issues: a bigger problem would be in the orbital filling diagram of phosphorus, where the 3p sub-level has five orbitals...I'm pretty sure that is too many orbitals (it's a pun, get it)! The last problem, which is rather critical, is all about identity. I mean, elements are like snowflakes, they're all unique, right? Well at least I though so, and I know for a fact that W and Au have different atomic numbers, so they should be different in reference to protons. if they are different in reference to protons, then they've got to be different in reference to electrons (judging that they are not ions in this case). Well, if we look to the electron configurations that you wrote for W and Au, they seem to be the exact bizarre. Well, that's all I've got. Enjoy!

  2. Well done, Cara! Cyrus, I believe Cara has drawn her orbital filling diagrams for W and Au correctly. I know it may be a bit difficult to see, but there are five more electrons with negative spin drawn on Au. This just happens to agree with your argument about the snowflakes! Also, Cara does show her consistency with the equal signs, you might just have to take another look. Cara, I know it is improper to restrict others from commenting on your blog, even if they may be pulling on your leg. Anyways, great work!

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