## Electron Spin

Maya_Peterson1C
Posts: 62
Joined: Fri Sep 28, 2018 12:28 am

### Electron Spin

I know the electron spin, or ms quantum number, is used because every electron had their own unique set of quantum numbers, but why is it +1/2 and -1/2? Was the value of 1/2 arbitrary?

Sydney Aurelio_Dis4B
Posts: 30
Joined: Fri Sep 28, 2018 12:28 am

### Re: Electron Spin

The +1/2 indicates an atom with one type of electron spin and the -1/2 indicates atoms with another type of electron spin. And they signify a direction of the spin (either spin up or spin down).

Laura Gong 3H
Posts: 89
Joined: Fri Sep 28, 2018 12:26 am
Been upvoted: 1 time

### Re: Electron Spin

+1/2 represents spin up and -1/2 represents spin down of the electrons. The numbers basically distinguish how the electron is spinning.

JiangJC Dis2K
Posts: 72
Joined: Fri Oct 12, 2018 12:16 am

### Re: Electron Spin

I was really confused on the Ms number number when I learned it in high school but I feel like Lavelle explained it really well. If you draw out the orbitals it makes a lot more sense. For example if n=2 and l=1 then you know this is the 2p orbital. p has three ml levels or three subshells (room for 6 electrons such as if it were 2p6). If the given were 2p2 then you would fill the boxes using Pauli and Hunds' rules to see if the electron that is particularly being asked about points up or down-up being +1/2 and down being -1/2. Hope that helps!