# Physics/Chemistry

posted by
**Hero** on
.

The following combinations of quantam numbers are not allowerd

1. n=3 l=0 m=-1

2. n=4 l=4 m=0

Can someone explain to me why the second one is not allowed.

Also check my explaination for the first one.

If L=0 then m also has to also =0

The s subshell (ℓ = 0) contains only one orbital, and therefore the mℓ of an electron in an s subshell will always be 0.