The number of radial nodes in $3s$ and $2p$-orbitals,respectively are

The electronic configuration of a nitrogen atom in its ground state is represented as follows:

In a potassium atom,the electronic energy levels are in the following order:

Consider the following statements:
$(a)$ Electron density in the $XY$ plane in $3d_{x^2-y^2}$ orbital is zero.
$(b)$ Electron density in the $XY$ plane in $3d_{z^2}$ orbital is zero.
$(c)$ $2s$ orbital has one nodal surface.
$(d)$ For $2p_z$ orbital,$YZ$ is the nodal plane.
Specify True or False.

The order of filling of electrons in the orbitals of an atom will be

If the $n^{th}$ specific period of the periodic table contains $\frac{(n+2)^2}{2}$ elements,then the maximum value of the azimuthal quantum number associated with that period is: