AP BIOLOGY

Detailed explanation-1: -The particles must be able to move around for diffusion to work. Diffusion does not occur in solids because the particles in a solid can only vibrate and cannot migrate from one location to another.

Detailed explanation-2: -Diffusion can take place in gases, liquids, or solids. In solids, particularly, diffusion occurs due to thermally-activated random motion of atoms-unless the material is at absolute zero temperature (zero Kelvin), individual atoms keep vibrating and eventually move within the material.

Detailed explanation-3: -The greater the difference in concentration, the quicker the rate of diffusion. The higher the temperature, the more kinetic energy the particles will have, so they will move and mix more quickly. The greater the surface area, the faster the rate of diffusion.