Which phrase is the * *best* * definition of * diffusion*? The transport of particles up a concentration gradient the movement of particles from a region of high concentration the movement through a cell membrane using ATP the movement of particles from a region of low concentration to a region of high concentration

The movement of particles from a region of high concentration

Explanation:

Diffusion is driven by Brownian motion of molecules of a fluid. The kinetic energy of the molecules causes them to collide randomly. Most of these collisions are inelastic. In a highly concentrated region, the molecules collide at a higher frequency hence there will be some form of pressure exerted by these colliding molecules to the boundaries of the system. If its an open system and there is a region of lower concentration, these molecules will disperse to these regions until they are evenly distributed. The 'system' will have transformed into a lower energy state following the law of entropy of molecular disorder.