Final answer:
In an atom, for the given set of quantum numbers (n = 4, l = 3, ml = -2, ms = + 1/2), only one electron can occupy that specific state because of the Pauli exclusion principle, which prevents two electrons from having the same set of quantum numbers.
Step-by-step explanation:
The question asks about the maximum number of electrons an atom can have with a specified set of quantum numbers. Given the quantum numbers n = 4, l = 3, ml = -2, ms = +1/2, we can deduce that these numbers correspond to an electron in a specific orbital. According to the Pauli exclusion principle, no two electrons can have the same set of four quantum numbers. For the given set of quantum numbers, the maximum number of electrons that can be in that state is one, because only one electron can have that specific combination of n, l, ml, and ms values at a time. If we were to have another electron in the same state, it would have to differ at least by the ms value, which can also be -1/2.