What is diffusion in the context of molecular movement?

Diffusion is characterized by the movement of molecules from an area of higher concentration to an area of lower concentration. This process occurs as molecules naturally move to achieve a more uniform distribution within a space. The driving force behind diffusion is the concentration gradient—molecules tend to spread out in order to balance the concentrations in their environment.

Diffusion does not require energy input; it is a passive process that occurs until equilibrium is reached. This principle is applicable to various states of matter, including solids, liquids, and gases, making it a fundamental concept in both biological and physical sciences. Understanding diffusion is crucial, as it plays a significant role in processes like respiration, nutrient absorption, and even the mixing of gases in the atmosphere.