what is diffusion.....
Answers
Answer:
diffusion movement of a substance from an area of higher concentration to lower concentration.
Diffusion is a mass transfer phenomenon that causes the distribution of a chemical species to become more uniform in space as time passes.In this case, species is a chemical dissolved in a solvent or a component in a gas mixture, such as the oxygen in air. The mass transfer of a species is the evolution of its concentration in space and time. If the concentration of a species is initially not uniform (the concentration might be greater in one region of a vessel than another, for example) then, over time, diffusion causes mass transfer in favor of a more uniform concentration.The driving force for diffusion is the thermal motion of molecules. At temperatures above absolute zero, molecules are never at rest. Their kinetic energy means that they are always in motion, and when molecules collide with each other frequently, the direction of the motion becomes randomized. In most cases, these collisions are common; even in air at atmospheric pressure, which hardly seems a "dense" fluid, each molecule collides with a neighbor every few nanoseconds.