Question

if n = 3, what is the maximum allowed value for ℓ?

Explanation:

Step1: Recall quantum - number rule

The angular - momentum quantum number $\ell$ ranges from $0$ to $n - 1$ for a given principal quantum number $n$.

Step2: Calculate maximum $\ell$ value

Given $n = 3$, then $\ell_{\text{max}}=n - 1=3 - 1 = 2$.

Answer:

2