# Can an orbital with a principal quantum number of n = 2 have an angular momentum quantum number of l = 2? True or false?

Feb 15, 2017

Absolutely... false.

What is the definition of the principal quantum number $n$? It's the energy level, if you recall. So, what is $n$ for the second energy level?

Recall that $l \le n - 1$, where $l$ is the angular momentum quantum number. Here are some questions for you:

1. What is the orbital shape described by $l = 2$? $s , p , d ,$ or $f$?
2. Verify that $l = 2$ is impossible for $n - 1$ where $n = 2$.

You should find that $l = 2$ is only possible for $n \ge 3$.