## Magnetic Quantum Numbers

Mary Shih 3J
Posts: 70
Joined: Wed Sep 30, 2020 9:39 pm

### Magnetic Quantum Numbers

After friday's ledture, I am still confused on how is m sub l (magnetic quantum #) equal to l-1. For example I thought subshell d or l=2 had 5 different types of orbitals. So why does l-1=m subL

Rose_Malki_3G
Posts: 80
Joined: Wed Sep 30, 2020 10:02 pm

### Re: Magnetic Quantum Numbers

m sub l does not only equal l - 1. It can equal a range of values; m sub l equals 1, l-1,... -1. For example. if l equals 2, then m sub l can be equal to 2, 1, 0, -1, -2.

Stephen Min 1I
Posts: 60
Joined: Wed Sep 30, 2020 10:01 pm

### Re: Magnetic Quantum Numbers

I'm not too sure what the professor wrote on the board for l, but m sub l should have values that range from -l to +l. So, in the case of the d subshell, m sub l could be any of -2,- 1, 0, 1, or 2.

Mary Shih 3J
Posts: 70
Joined: Wed Sep 30, 2020 9:39 pm

### Re: Magnetic Quantum Numbers

Rose_Malki_3L wrote:m sub l does not only equal l - 1. It can equal a range of values; m sub l equals 1, l-1,... -1. For example. if l equals 2, then m sub l can be equal to 2, 1, 0, -1, -2.

So the m sub l number is the number it starts with and it ranges to the negative value of l? Like l=1 is starts at 1 and ends at the negative number, -1.

Brianne Conway 1D
Posts: 66
Joined: Wed Sep 30, 2020 9:36 pm

### Re: Magnetic Quantum Numbers

Like Rose said, m sub l ranges from l to -l. That way, there are enough different values of m sub l to signify each configuration for each type of orbital. For example, for an s-orbital (l=o), m sub l can only be 0, signifying the only configuration for the s-orbital. For a p-orbital (l=1), which has 3 different configurations, m sub l can be 1, 0, or -1, so there are exactly enough different values of m sub l to signify the different configurations. Same for d- and f-orbitals.

Juwon Lim 2A
Posts: 66
Joined: Wed Sep 30, 2020 9:49 pm

### Re: Magnetic Quantum Numbers

I was also confused on the way he wrote the list of possible ml values at first. What he means by ml = l, l-1, ..., -l is that ml can be any value between l and -l. If l = 2, the possible ml values are ml = 2, 1, 0, -1, -2.
On a side note, ml values represent the orientation of the orbital. Therefore, if l = 2, this is the d-Orbital, which has 5 possible orbitals. ml can equal 5 values: 2, 1, 0, -1, -2, which corresponds to the 5 d-Orbitals

Vince Li 2A
Posts: 64
Joined: Wed Sep 30, 2020 9:37 pm

### Re: Magnetic Quantum Numbers

It makes sense, if you have an l=0, then you can only have one orientation because it is a sphere. If you have l = 1, you have three orientations, due to how there are 3 values that m sub l can be, such as the Px, Py, and Pz. The same goes with the d orbital, since there are 5 orientations it can become. Now, I don't exactly know how you know each number corresponds to each orientation, but I am sure that the professor might clarify that at some point.