Stokes-Einstein formula
On the basis of the Brownian motion, due to constant collisions between molecules of a liquid and dispersed particles, purely random motion in arbitrary directions is imparted to these as well.
The speed of motion depends directly on the particle size. This relationship is described by the Stokes-Einstein formula. More precisely, this formula actually addresses the diffusion coefficient rather than the speed of motion. In addition to the temperature, the viscosity of a liquid is an important constant in the Stokes-Einstein formula.
