Select the set of quantum numbers which is $NOT$ associated with any electron in $Cr$ $(Z = 24)$.

What are the total number of electrons present in $s$ and $p$ orbitals respectively in the ground state of an argon atom $(Z = 18)$?

How many nodal (angular) planes are present in the $d_{xy}$ orbital? Which are they?

For the given quantum numbers,write the name of the subshell,the values of the magnetic quantum number $(m_l)$,and the number of orbitals:
$(i) \ n = 3, \ l = 2$
$(ii) \ n = 4, \ l = 3$
$(iii) \ n = 2, \ l = 0$
$(iv) \ n = 5, \ l = 1$

The angular wave function $A(\theta, \phi)$ for a given atomic orbital is $\frac{1}{2}\sqrt{\frac{3}{\pi}}\cos \theta$ in the polar coordinate system. Identify the orbital.

The extra stability of half-filled subshells is due to:
$(A)$ Symmetrical distribution of electrons
$(B)$ Smaller coulombic repulsion energy
$(C)$ The presence of electrons with the same spin in non-degenerate orbitals
$(D)$ Larger exchange energy
$(E)$ Relatively smaller shielding of electrons by one another
Identify the correct statements.