ORIGINAL QUESTION:
Which of the following substances is most likely to be diamagnetic?

A.) Hydrogen
B.) Iron
C.) Cobalt
D.) Sulfur

Answer in the book says Iron, which is answer choice C (But that's actually cobalt).

I'm actually really confused on this because I did draw out the electron configurations of the others to double check and for Iron it has unpaired electrons.

[Ar] 4s^2 3d^6

The D subshell has 5 orbitals, each can hold 2 electrons at most. According to Hund's rule the filling order for these boxes is to fill it to make each electron have their own space. [Okay this is hard to explain its like about 5am but if you're good at chemistry you probably know what i mean].

[ i i ] [l l ] [l ] [l ] [l ] [l ]

I thought diamagnetic had all paired electrons in the orbitals and paramagnetic had unpaired electrons in orbitals.

EDIT: I thought the only screwy ones with this was Cr and Cu. Which allowed you to take from the 4s subshell.

Post edited at 3:02 am on June 11, 2012 by DaffySpaffy