Which of the following specific combinations of the four quantum numbers $(n, l, m_l, m_s)$ is stric

Question

Which of the following specific combinations of the four quantum numbers $(n, l, m_l, m_s)$ is strictly forbidden by the rules of quantum mechanics for any electron in an atom?

Professor PC Thomas Classes · Answer

(b) : Let's analyze the constraints on quantum numbers. For a given $n$, $l$ ranges from $0$ to $n-1$. For a given $l$, $m_l$ ranges from $-l$ to $+l$. In option (b), $n=4$ and $l=2$. The allowed values for $m_l$ are $-2, -1, 0, +1, +2$. The provided value of $m_l = -3$ falls outside this strictly permissible range, rendering this entire combination quantum mechanically impossible.