The associated quantum number is the main total angular momentum quantum number j. It can take the following range of values, jumping only in integer steps: | ℓ ℓ − − s | ≤ ≤ j ≤ ≤ ℓ ℓ + s where ℓ is the azimuthal quantum number (parameterizing the orbital angular momentum) and s is the spin quantum number (parameterizing the spin).