Diffusion is the net movement of molecules from an area where they are at a higher concentration to areas where they are at a lower concentration. This is due to the random movement of the molecules. The difference in the concentration of a substance between two areas is called the concentration gradient .

How do molecules move when they diffuse?

During diffusion, substances move from an area of high concentration to an area of low concentration, until the concentration becomes equal throughout a space. ... There is net movement of molecules from the outside to the inside of the cell until the concentrations are equal on both sides.

What happens to molecules when they diffuse?

Diffusion is the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration. ... it is the random motion of the molecules that causes them to move from an area of high concentration to an area with a lower concentration.