Question

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

Answer 1

Diffusion is best defined as the natural passive movement of molecules from regions of higher concentration to regions of lower concentration until equilibrium is reached.

Step-by-step explanation:

The best definition of diffusion is the movement of molecules from an area of high concentration to an area of low concentration. This process occurs until there is an equal concentration of the molecules on both sides of a membrane, reaching equilibrium. Diffusion is a passive process, meaning it does not require energy since it is driven by the inherent kinetic energy of molecules and the existing concentration gradient. An everyday example of diffusion is the spreading of perfume scent throughout a room once sprayed.

Answer 2

The movement of particles from a region of high concentration

Step-by-step 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.