## Assigning Quantum Numbers to Different Elements

Anna O 2C
Posts: 98
Joined: Fri Sep 28, 2018 12:19 am

### Assigning Quantum Numbers to Different Elements

I'm struggling to clarify how to utilize ml and ms for quantum numbers. I understand that n is the period of the element, and that l is for the orbital the valence electrons, but I'm not sure on the concept behind the ml and ms as well as the numbers when an element is in the d-block.
Say for example Chromium (period 4).
N=4 because it is in period 4 (or is it 3 because the d-orbital is technically 3d?)
l=2 because it is in the d-block
ml can be -2,-1,0,1,2 (Can we figure this out or can we only know the range?)
ms can be either -1/2 or +1/2

Thanks!

klarratt2
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

### Re: Assigning Quantum Numbers to Different Elements

ml is the magnetic quantum number. This just tells you which orbital the electron is in. For example, an electron in chromium could either be in the -2, -1, 0, 1, or 2 orbital.

ms is spin magnetic quantum number. This tells you whether the electron has up spin or down spin (the two electrons in an orbital will have opposite spins; one will be up and one will be down).

I'm not sure if there is a way to find out the specific ml value of an electron. Each number in the range is just a possibility for what orbital the electron could be found in.

Sorry that this doesn't fully answer the question but I hope it helps!

Anna O 2C
Posts: 98
Joined: Fri Sep 28, 2018 12:19 am

### Re: Assigning Quantum Numbers to Different Elements

klarratt2 wrote:ml is the magnetic quantum number. This just tells you which orbital the electron is in. For example, an electron in chromium could either be in the -2, -1, 0, 1, or 2 orbital.

ms is spin magnetic quantum number. This tells you whether the electron has up spin or down spin (the two electrons in an orbital will have opposite spins; one will be up and one will be down).

I'm not sure if there is a way to find out the specific ml value of an electron. Each number in the range is just a possibility for what orbital the electron could be found in.

Sorry that this doesn't fully answer the question but I hope it helps!

This definitely cleared up some things for me regarding the ml values. Thank you!!