The quantum number defines the shape of an orbital. spin magnetic principal angular momentum psi The subshell contains only one orbital. 5d 6f 4s 3d 1p The angular momentum quantum number is 3 in orbitals. s p d f a The principal quantum number of the first d subshell is 1 2 3 4 0 [Ar]4s^23d^104p^3 is the electron configuration of a(n) atom. As V P Sb Sn