Magnetic and spin quantum number of an electron are $-1$ and $+1/2$ respectively. This electron cannot be in

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

Between $4s$ and $3d$ orbitals,which one has higher energy and why?

Which orbital is represented by the wave function $\Psi_{310}$?

If the number of radial nodes in an $s$-orbital is $(n - 1)$,and the question asks for the orbital where the number of nodes is $(n - 1)$,which orbital corresponds to the given expression $(n - 1)$?

The ground state energy of a hydrogen atom is $-13.6 \ eV$. Consider an electronic state $\Psi$ of $He^+$ whose energy,azimuthal quantum number,and magnetic quantum number are $-3.4 \ eV$,$2$,and $0$ respectively. Which of the following statement$(s)$ is(are) true for the state $\Psi$?
$(1)$ It has $2$ angular nodes
$(2)$ It has $3$ radial nodes
$(3)$ It is a $4d$ state
$(4)$ The nuclear charge experienced by the electron in this state is less than $2e$,where $e$ is the magnitude of the electronic charge.