## Electron Spin

Kate_Santoso_4F
Posts: 72
Joined: Fri Sep 28, 2018 12:29 am

### Electron Spin

In regards to electron spin for unpaired electrons, how do we know if the electron is spinning clockwise or counterclockwise? Based on what I've seen in class, an unpaired electron has a counterclockwise spin with a magnetic spin quantum number of +1/2. Why is this so?

Cody Do 2F
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

### Re: Electron Spin

I don't believe we've been taught a way to calculate whether an electron is +1/2 or -1/2. The important parts to remember regarding electron spin are:
+1/2 is counterclockwise and -1/2 is clockwise
Pauli Exclusion Principle: Only two electrons per orbital. If there are two electrons, then they spin opposite directions.
Hund's Rule: Put one electron in each orbital first BEFORE putting two electrons in one orbital. Make sure all the electrons spin the same directions.

charlotte_jacobs_4I
Posts: 63
Joined: Fri Sep 28, 2018 12:29 am

### Re: Electron Spin

In terms of this rule is the up arrow electron positive or negative 1/2?

Kate_Santoso_4F
Posts: 72
Joined: Fri Sep 28, 2018 12:29 am

### Re: Electron Spin

The up arrow electron is positive 1/2 which indicates a counterclockwise spin and the down arrow electron is negative 1/2 which indicates a clockwise spin.