Magnetic Quantum Number

Cam Bear 2F
Posts: 60
Joined: Thu Jul 27, 2017 3:01 am

Magnetic Quantum Number

Can anyone explain what the Magnetic Quantum Number (ml) is and how you figure out what values it can be? I don't understand how to apply l, l-1,...-l. Thanks!

Catherine Yang 3G
Posts: 24
Joined: Fri Sep 29, 2017 7:06 am
Been upvoted: 2 times

Re: Magnetic Quantum Number

The magnetic quantum number refers to the different orbitals of a sub-shell (for example, the px , py , and pz orbitals). It is different from the angular momentum quantum number (l) that only describes whether it's s, p, d, or f.

ml can take on the positive and negative values of l. For example, if l is 1 (the p-orbital), then ml can be -1, 0, or 1. These three possible options for ml refer to the three different orientations of the p orbitals. And if l is 2 (the d-orbital), then ml can be -2, -1, 0, 1, or 2. These five possible options describe all the different d orbital orientations.

Curtis Tam 1J
Posts: 105
Joined: Thu Jul 13, 2017 3:00 am

Re: Magnetic Quantum Number

Catherine Yang 3G wrote:The magnetic quantum number refers to the different orbitals of a sub-shell (for example, the px , py , and pz orbitals). It is different from the angular momentum quantum number (l) that only describes whether it's s, p, d, or f.

ml can take on the positive and negative values of l. For example, if l is 1 (the p-orbital), then ml can be -1, 0, or 1. These three possible options for ml refer to the three different orientations of the p orbitals. And if l is 2 (the d-orbital), then ml can be -2, -1, 0, 1, or 2. These five possible options describe all the different d orbital orientations.

Do the ml values correspond to a specific orientation? Like do px orbitals correspond to ml=-1 for example? Thanks!

Janet Nguyen 2H
Posts: 51
Joined: Fri Sep 29, 2017 7:05 am

Re: Magnetic Quantum Number

Catherine Yang 3G wrote:
Do the ml values correspond to a specific orientation? Like do px orbitals correspond to ml=-1 for example? Thanks!

Yes I'm pretty sure that the ml values correspond to a specific orientation, but I'm also pretty sure that we won't need to know the content that specifically :)

Catherine Yang 3G
Posts: 24
Joined: Fri Sep 29, 2017 7:06 am
Been upvoted: 2 times

Re: Magnetic Quantum Number

I think that Dr. Lavelle mentioned that the values of ml don't correspond with any specific orientation because it's arbitrary which number to assign to which orbital. The values of ml are especially complicated with the five d orbitals.