Quantum numbers: If the principal quantum number of an electron is n = 5, which one of the following is NOT an allowed magnetic quantum number m_l for the electron?

Question

Quizplus · Accepted Answer

The allowed magnetic quantum numbers for an electron are given by the equation: 
-mℓ ≤ mS ≤ +mℓ 
where mℓ is the magnetic quantum number (range from -l to +l). 
Since the principal quantum number n = 5, the maximum value of mℓ is 4. Thus, the allowed magnetic quantum numbers for this electron are:
-mℓ ≤ mS ≤ +mℓ
-4 ≤ mS ≤ +4
Therefore, the only choice that is not an allowed magnetic quantum number is E (5).

Quantum Numbers: If the Principal Quantum Number of an Electron