Which of the Following Set of Quantum Numbers {N, ℓ

Multiple Choice

Which of the following set of quantum numbers {n, ℓ, m_ℓ, m_s} is allowed?

A) {2, 1, 0, −1/2}
B) {2, 1, 2, +1/2}
C) {2, 2, 0, −1/2}
D) {2, −1, 0, +1/2}
E) {2, 2, 1, −1/2}