Finding Magnetic Quantum Number

[Crystal Hsueh 2L]

Can someone explain how to find the magnetic quantum number (ml)? I understand the relationship between the first two quantum numbers but I'm having trouble understanding how to find the third. Thanks so much :)

[Annika Tamaki 1E]

The values of m can range between -l and +l. For every l value, there are 2l+1 values that m can be. Hope this helps!

[Samantha Pedersen 2K]

Once you have determined the value of L (the second quantum number), the allowed values of ml (the third quantum number) are L, L-1,... all the way down to -L.

For example, if L is equal to 1, then ml can be equal to any of 1, 0, or -1.

Then, we arbitrarily decide that ml=1 represents the Px orbital, ml=0 represents the Py orbital, and ml = -1 represents the Pz orbital. I would guess that the assumption for the value of ml and the corresponding orbital would be given to us on an exam.

Based on the above assumption, if an electron is in the first orbital of the P subshell, then it has ml=1. If the electron is in the second orbital of the P subshell, then it has ml=0 and so on. I hope this helps!