What is a shell in the context of atomic structure?

Which electronic configuration represents a noble gas?

Given below are two statements:
Statement $I$ : For a given shell,the total number of allowed orbitals is given by $n^2$.
Statement $II$ : For any subshell,the spatial orientation of the orbitals is given by $-l$ to $+l$ values including zero.
In the light of the above statements,choose the correct answer from the options given below:

For which of the following orbitals is the value of $(n + l)$ maximum?

Find the number of unpaired electrons for copper in ground state configuration.

For azimuthal quantum number $l = 3$,the maximum number of electrons will be