Degeneracy of hydrogen energy levels

lonewolf5999
Messages
33
Reaction score
0
Consider a universe where the intrinsic spin of the electron is S = 5/2, but all other parameters and Rules of Quantum Mechanics are the same. Find the degeneracy of the n=1 and n=2 levels of hydrogen.

My understanding is that electrons in an atom have 4 quantum numbers n,l,ml,ms, and different electrons can't have all 4 quantum numbers being the same. Since we have S = 5/2, we can have ms = -5/2, -3/2, -1/2, 1/2, 3/2, 5/2. For n = 1, usual rules tell us l = 0 and ml = 0, so since ms can have 6 different values, the n = 1 state has a degeneracy of 6 and can accept up to 6 electrons.

For n = 2, l = 0, the reasoning is the same as above, so that orbital also has a degeneracy of 6. For n = 2, l = 1, ml = -1, 0 or 1, and for each of these ml we can have 6 different ms, so we have a degeneracy of 18 for n = 2, l = 1 and thus a total degeneracy of 24 for n = 2.

Is this reasoning correct, or am I missing something in the problem?
 
Last edited:
Physics news on Phys.org
Yeah, you got it.
 
Ok, thanks for the reply!
 
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top