The maximum number of electrons present in an orbital with $n=4, l=3$ is

The energy of atomic orbitals in a given shell follows the order:

Provide the orbital electronic configuration for the following elements: $Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca$.

Identify the correct statements:
a) In an atom,the maximum number of electrons with $n=4$ and $m_s=+\frac{1}{2}$ is $16$.
b) There are $4$ subshells associated with $n=5$.
c) $n=2, l=1, m_l=0$ and $m_s=-\frac{1}{2}$ is a possible set of quantum numbers.
d) The number of radial nodes for $3s$ orbital is $2$.

The number of unpaired electrons in $1s^2 2s^2 2p^3$ is:

The maximum number of electrons that can be accommodated in a $3d$ subshell is