How is the angular node determined? State the number of angular nodes for $s, p, d,$ and $f$ orbitals.

The configuration $1s^2 2s^2 2p^5 3s^1$ shows

The total number of orbitals present for principal quantum number,$n=4$ is

How are atomic orbitals (electrons) identified or distinguished?

When the azimuthal quantum number has the value of $2$,the number of orbitals possible are

Consider the following pairs of electrons:
$(A)$ $(a)$ $n=3, l=1, m_{l}=1, m_{s}=+\frac{1}{2}$
$(b)$ $n=3, l=2, m_{l}=1, m_{s}=+\frac{1}{2}$
$(B)$ $(a)$ $n=3, l=2, m_{l}=-2, m_{s}=-\frac{1}{2}$
$(b)$ $n=3, l=2, m_{l}=-1, m_{s}=-\frac{1}{2}$
$(C)$ $(a)$ $n=4, l=2, m_{l}=2, m_{s}=+\frac{1}{2}$
$(b)$ $n=3, l=2, m_{l}=2, m_{s}=+\frac{1}{2}$
The pair$(s)$ of electrons present in degenerate orbitals is/are...... .