The quantum number for an electron within an atom is n = 3, l = 1, ml = 1, ms = 1/2. Which quantum number is not allowed for another electron within the same atom?
n = 3, l = 0, ml = 0, ms = 1/2
n = 3, l = 1, ml = -1, ms = 1/2
n = 3, l = 1, ml = 1, ms = -1/2
n = 1, l = 0, ml = 0, ms = 1/2