# Formula: Angular Momentum / Spin of a Quantum Particle Angular momentum quantum number    Planck's Constant

## Angular momentum

Unit
Amount of angular momentum of a quantum mechanical particle (for example, an electron).
• Orbital angular momentum quantum numbers: l= 0, 1, 2, ...
• Spin quantum numbers: l = 1/2, 3/2, 5/2, ...

## Angular momentum quantum number

Unit
The angular momentum quantum number accepts non-negative numbers in +1 steps: $$l \in \left\{ 0, \, \frac{1}{2}, \, 1, \, \frac{3}{2}, \, 2,~... \right\}$$

## Reduced Planck's constant

Unit
Reduced Planck's constant is a physical constant that often appears in the equations of quantum mechanics. It has the value: $$\hbar ~=~ \frac{h}{2 \pi} ~=~ 1.054 \, 572 ~\cdot~ 10^{-34} \, \text{Js}$$.

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