Question: what are the four quantum numbers for the last electron in for cr3+?
Answer: The correct quantum numbers for the last electron in Chromium: $Cr = [Ar] 3d^{5} 4s^{1}$ Thus n =3, l = 2, m = +2, s = +1/2 Also, if these same quantum numbers are used, it is the same with the last quantum number of manganese.