Physics
Azimuthal Quantum Number (l)
Quick fact
The azimuthal quantum number can take integer values from 0 to (n-1), where n is the principal quantum number. For example, when n=3, l can be 0, 1, or 2, corresponding to 3s, 3p, and 3d orbitals.
Why this is interesting
You know that electrons orbit the nucleus in clouds, but why are some clouds shaped like dumbbells and others like clovers? The secret lies in the azimuthal quantum number.