## degeneracy

505166714
Posts: 50
Joined: Fri Sep 28, 2018 12:17 am

### degeneracy

How can I interpret the meaning of degenerate? How should I answer the question on test2 that asks about the degeneracy of a 4p orbital?

MaanasO 1A
Posts: 72
Joined: Fri Sep 28, 2018 12:26 am

### Re: degeneracy

Hi!

So degeneracy refers to the same energy level, BUT this is not the same as the principal quantum number N. Remember Prof Lavelle's drawing of the orbitals in lecture? He drew 1s, then a line for 2s, and then 3 lines for 2p. All of the orbitals in the same subshell (s, p, d, f) are expected to have the same exact energy level. In other words, an electron in 2px wouldn't have any more or less energy than an electron in 2py. Now, technically this doesn't hold true for d-orbitals, but that's beyond the scope of the class. Since the p subshell has 3 orbitals, its degeneracy would be 3.

Hope that helps!

Grace Kim 1J
Posts: 60
Joined: Fri Sep 28, 2018 12:18 am
Been upvoted: 1 time

### Re: degeneracy

Degeneracy means the electron orbitals have the same energy level.

To determine the degeneracy of orbitals,
Consider the three orbitals s, p, d:
s orbital
l=0; the ml would be 0, therefore no degeneracy
p orbital
l=1; the ml would be -1, 0 +1, therefore degeneracy=3
d orbital
l=2, ml would be -2, -1, 0 +1, +2 , therefore degeneracy=5