Answer
See the answer below.
Work Step by Step
$0\leq\ell\leq n-1$
$\begin{smallmatrix}
&n &\ell & Valid\ ?\\
\hline\\
2s&2&0&\surd\\
2d&2&2&\times\\
3p&3&1&\surd\\
3f&3&3&\times\\
4f&4&3&\surd\\
5s&5&0&\surd
\end{smallmatrix}$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.