J.R. S. answered 04/15/20
Ph.D. University Professor with 10+ years Tutoring Experience
n is the principal quantum number indicating the shell (1, 2, 3, ....etc)
ℓ is the angular quantum number indicating the orbital or shape of the orbital (s=0, p=1, d=2, f=3 etc)
5s
n = _5__ ℓ = __0__
2p
n = _2__ ℓ = __1__
6d
n = _6__ ℓ = _2___