Task: Text Categorization
Input (English): The quantum coupling of this quantity is described using Clebsch-Gordan coefficients. If a system's Lagrangian is rotationally invariant, this quantity is conserved due to Noether's Theorem. For atomic orbitals, this quantity, represented as the azimuthal quantum number, must be an integer multiple of h bar, and its intrinsic form was quantized in the Stern-Gerlach experiment and is called [*] spin. Both Kepler's Second Law and gyroscopes demonstrate the conservation of this quantity in the absence of net external torque. For 10 points, name this cross product of position and linear momentum, symbolized with L.
Output (English): Science