The number of angular and radial nodes of $4d$ orbital respectively are

In the ground state,an element has $13$ electrons in the $M$ shell. The element is

Statement $A$: In a potassium atom,the $19^{th}$ electron enters the $4s$-orbital instead of the $3d$-orbital.
Reason $R$: The $(n + l)$ rule is followed to determine the minimum energy of an orbital.

$A$ hydrogen atom has only one electron,so mutual repulsion between electrons is absent. However,in multielectron atoms,mutual repulsion between the electrons is significant. How does this affect the energy of an electron in the orbitals of the same principal quantum number in multielectron atoms?

An electron having quantum numbers $n = 4, l = 3, m = 0, s = -1/2$ is present in which orbital?

Write the values of $n, l, m_{l}, m_{s}$ for $4f$.