Spin (physics) discrete angular momenta despite having no orbital angular momentum. In some ways, spin is like a vector quantity; it has a definite magnitude, and it has a "direction" (but quantization makes this "direction" different from the direction of an ordinary vector). All elementary particles of a given kind have the same magnitude of spin angular momentum, which is indicated by assigning the particle a spin quantum number. The SI unit of spin is the (N·m·s) or (kg·m·s), just as with classical angular momentum. In practice, spin is given as a dimensionless spin quantum number by dividing the spin angular momentum
Quantity the principal distinction between continuity (continuum) and discontinuity. Under the name of multitude comes what is discontinuous and discrete and divisible ultimately into indivisibles, such as: "army, fleet, flock, government, company, party, people, mess (military), chorus, crowd", and "number"; all which are cases of collective nouns. Under the name of magnitude comes what is continuous and unified and divisible only into smaller divisibles, such as: "matter, mass, energy, liquid, material"—all cases of non-collective nouns. Along with analyzing its nature and classification, the issues of quantity involve such closely related topics as the relation of magnitudes and multitudes, dimensionality, equality, proportion,