Q: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
The square of this quantity's operator is the Casimir invariant of the SO(3) Lie Algebra, and this quantity is crossed to p in the definition of the Laplace-Runge-Lenz vector. Yrast refers to a minimum of energy for a given value of this quantity, which is often added using expansion coefficients named for Clebsch and Gordan. Often specified using term symbols, two types of it are coupled in heavy atoms by JJ-coupling or in lighter ones by Russell-Saunders coupling. It is the Noether charge associated with rotational invariance, and this quantity's derivative with respect to time is equal to the net torque. For ten points, identify this quantity which comes in orbital and spin types and is equal to moment of inertia times angular velocity.
A:
Science