Explain why the quantum number set (2, 1, -2, -½) is not possible for an electron in an atom? Im so lost. I know the rules but I keep getting tripped up medal!

Question

jfraser · Answer

the allowed values for $m_l$ are +/-L, so if L = 1, $m_l$ cannot possibly equal -2

ams98 · Answer

Okay so the first two in the set are right but because the L is 1 the m cannot be -2?

ams98 · Answer

@JFraser

jfraser · Answer

the values of the second depend on the first, and the values of the third depend on the second. the third value violates the allowed rules, so the whole configuration is not allowed

ams98 · Answer

That makes sense! Thanks so much for breaking it down for me!

jfraser · Answer

YW