## For Ms (spin up, spin down)

$H_{\psi }=E_{\psi }$

1-D: $E_{TOTAL}\psi (x)=E_{k}\psi (x)+V(x)\psi(x)=-\frac{h^{2}}{8\pi ^{2}m}\frac{d^{2}\psi(x)}{dx^{2}}+V(x)\psi(x)$

Cooper_Geralds_2E
Posts: 37
Joined: Wed Sep 30, 2020 10:07 pm

### For Ms (spin up, spin down)

For the value of Ms, is there an arrow always given to indicate whether it is spin up or spin down or is there another way to determine whether the value is + or -1/2?

Jordan Tatang 3L
Posts: 53
Joined: Wed Sep 30, 2020 9:31 pm
Been upvoted: 3 times

### Re: For Ms (spin up, spin down)

I think the main notation for this would just be the up/down arrows in the orbitals.

Courtney Situ 3D
Posts: 47
Joined: Wed Sep 30, 2020 10:03 pm

### Re: For Ms (spin up, spin down)

Hi there!
I thought you were asking if the +1/2 and -1/2 corresponded to a specific arrow (up/down). Generally, I believe the up arrow, which corresponds to spin up, represents a spin number of +1/2. Therefore, the down arrow, which corresponds to spin down, represents a spin number of -1/2.

Hope that helps!

Andrew Yoon 3H
Posts: 36
Joined: Wed Sep 30, 2020 9:36 pm

### Re: For Ms (spin up, spin down)

For +1/2, I think it is supposed to represent spin up, and -1/2 is supposed to represent spin down.

Mari Williams 2k
Posts: 31
Joined: Wed Sep 30, 2020 9:53 pm

### Re: For Ms (spin up, spin down)

Do we ever use 0? Is there ever a situation in which an electron has no spin?

Jonathan Banh 1G
Posts: 42
Joined: Wed Sep 30, 2020 9:33 pm

### Re: For Ms (spin up, spin down)

I believe that the only values for the spin quantum number are $m_s=\pm \frac{1}{2}$. When determining the value for $m_s$, this is denoted by the arrows in the orbitals, where if they are pointing upwards, the spin is 1/2 while if they are pointing downwards, the spin is -1/2. On a side note, it is important to remember that electrons tend to fill up all the orbitals before pairing up together, which can affect your value of $m_s$.

Jack_Pearce_2F
Posts: 35
Joined: Wed Sep 30, 2020 9:48 pm

### Re: For Ms (spin up, spin down)

It's usually just an arrow unless otherwise stated (i.e. if the questions says that another electron with the same first three quantum numbers and an Ms of +1/2 is in an orbital, you know the other electron will have -1/2).