How many electrons in an atom can have the quantum numbers $n = 3, l = 2, m = +2, s = +1/2$?

What is the electronic configuration of $Cu^{2+} (Z = 29)$ in its ground state?

How many electrons are present in an atom with atomic number $Z = 104$ for which $(n + l) = 8$?

Which of the following statements are correct?
$(a)$ When an electron in an atom moves from $n=4$ to $n=2$,it gains energy.
$(b)$ An electron in a $3p$ orbital would have less energy than an electron in a $2p$ orbital.
$(c)$ $A$ $3s$ subshell has a maximum of $2$ electrons.
$(d)$ $A$ $3^{rd}$ orbit may contain a maximum of $10$ electrons.

The principal quantum number represents:

Which of the following principles/rules limits the maximum number of electrons in an orbital to two?