I have no idea what's going on here. I tried putting all the electrons into orbitals to get the answers in the picture, but it says they are wrong, and I don't know how to find the correct one. If anyone could explain this to me, please, I'd really appreciate it.




/e
I just figured out that the diamagnetic ones are C2, N2, F2, while the other two are paramagnetic, but I still don't really get how.

I've been taking the total number of electrons, and putting them into orbitals.
For ex. I take B2, which has 10 electrons, and do 1s2 2s2 2p6 which is 10, so they're all filled. I know I'm doing something wrong...

This post was edited by furbyjs on Apr 17 2013 12:33pm

Can go over more detail later, but B2 works like this:

A boron atom has three valence electrons. (Remember that you are ignoring the inner-shell 1s electrons.) Thus, for B2 you must place six electrons in MOs. Four of these electrons fully occupy the sigma 2s and sigma star 2s
MOs, leading to no net bonding. The last two electrons are put in the bonding pi MOs; one electron is put in one pi 2p MO and the other electron is put in the other pi 2p MO, with the two electrons having the same spin.

Hence it is paramagnetic.