## Quantum Numbers

205389184
Posts: 80
Joined: Sat Sep 07, 2019 12:18 am

### Quantum Numbers

I am having a bit trouble understanding the concept behind the quantum number ms. How do we determine this value?

christabellej 1F
Posts: 93
Joined: Sat Aug 17, 2019 12:17 am

### Re: Quantum Numbers

The quantum number ms is the magnetic spin of the electron. In the Pauli Exclusion principle, it states that there can only be a maximum of two electrons per orbital, and that the two electron spins must be paired. That basically means that one electron will spin in an upwards direction and one in a downwards direction. The magnetic spin quantum represents that, with +1/2 representing the upwards spin and the -1/2 representing the downwards spin. This value can only be +1/2 and -1/2.

Emily Chirila 2E
Posts: 91
Joined: Sat Jul 20, 2019 12:16 am

### Re: Quantum Numbers

I think that all you need to know is that the quantum number ms is only valid if its value is + or - 1/2 and that it refers to the spin of the electron, with the 2 electrons in an orbital having opposite spins (one has +1/2 one has -1/2).

Eva Zhao 4I
Posts: 86
Joined: Sun Sep 29, 2019 12:16 am

### Re: Quantum Numbers

ms is usually pretty arbitrary unless the question specifies that the electron is +1/2 or -1/2. The most important thing to remember is that no two electrons in an atom can have the exact same four quantum numbers, so if one electron is +1/2, the other in the pair is -1/2.

ThomasNguyen_Dis1H
Posts: 81
Joined: Fri Aug 30, 2019 12:17 am

### Re: Quantum Numbers

ms can only have the value of +/- 1/2. When drawing the electron configurations with arrows pointing up and down, you can see that each orbital can only have 2 arrows, one pointing up and one pointing down. This represents ms. One electron can have the value of 1/2 while the other electron has the value of -1/2 (down)

Posts: 49
Joined: Wed Sep 18, 2019 12:20 am

### Re: Quantum Numbers

Are there any equations that use ms? Will we only ever need to know its application as we have learned it before, or will we need to apply it somehow?

105289321
Posts: 49
Joined: Sat Sep 07, 2019 12:15 am

### Re: Quantum Numbers

By writing out the electron configuration and seeing whether the arrow is pointed up or down for any specific electron