What is the process of particles moving from an area of higher concentration to an area of lower concentration known as?

The process of particles moving from an area of higher concentration to an area of lower concentration is known as diffusion. This fundamental concept in biology and chemistry describes how substances naturally spread out in a medium, whether that medium is a gas, liquid, or even solid. In diffusion, molecules tend to move until they reach an equilibrium state, where the concentration of the substance is uniform throughout the space.

Diffusion occurs without the need for external energy, as it is driven solely by the kinetic energy of the particles. For example, if you were to open a bottle of perfume in a room, the fragrance molecules would disperse throughout the air, transitioning from a concentrated area near the bottle to a lower concentration throughout the room.

Understanding diffusion is essential in various biological processes, such as gas exchange in the lungs and the absorption of nutrients in cells. The other processes listed, such as osmosis, filtration, and active transport, involve different mechanisms and energy requirements, distinguishing them from the passive nature of diffusion.