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
Orders of magnitude (numbers) Orders of magnitude (numbers) This list contains selected positive numbers in increasing order, including counts of things, dimensionless quantity and probabilities. Each number is given a name in the short scale, which is used in English-speaking countries, as well as a name in the long scale, which is used in some of the countries that do not have English as their national language. ISO: yocto- (y) ISO: zepto- (z) ISO: atto- (a) ISO: femto- (f) ISO: pico- (p) ISO: nano- (n) ISO: micro- (μ) ISO: milli- (m) ISO: centi- (c) ISO: deci- (d) ISO: deca- (da) ISO: hecto- (h) ISO: