For $n = 4$,what is the total number of orbitals?

Which is the correct order of increasing energy of the listed orbitals in the atom of titanium? (At. no. $Z = 22$)

Statement $A$: An orbital can accommodate a maximum of two electrons.
Reason $R$: Two electrons in an orbital produce opposite magnetic fields.

The five valence electrons of $_{15}P$ are represented as shown in the figure. If the spin quantum number of $B$ and $Z$ is $+1/2$,which of the following groups has three identical quantum numbers?

Which of the following outer electronic configurations represents argon?

The angular momentum of an electron in a $d$ orbital is equal to: