ANS:C - concentration

Concentration diffusion, also known as Fickian diffusion, is the process by which molecules move from an area of higher concentration to an area of lower concentration, resulting in the equalization of concentration throughout a system. This movement occurs due to the random thermal motion of particles, with molecules naturally tending to spread out and mix with one another. In concentration diffusion, the driving force for the movement of molecules is the concentration gradient, which represents the difference in concentration between two regions. Molecules move from regions of higher concentration to regions of lower concentration until equilibrium is reached, where there is no net movement of molecules. This process is fundamental in various natural and industrial phenomena, including the diffusion of gases, liquids, and solids. It plays a crucial role in processes such as the transport of nutrients across cell membranes, the dispersion of pollutants in the environment, and the mixing of chemicals in solution. In many cases, concentration diffusion is governed by Fick's laws of diffusion, which describe the rate and behavior of diffusion processes.