Diffusion moves a substance until what condition is reached?

1. Diffusion is a passive process of transport. 2. A single substance moves from high concentration to low concentration until the concentration is equal across a space. 3. Molecules do not stop moving at that point, they simply produce no net movement from one area to another. 4. That state of movement without net transfer is called dynamic equilibrium, so complete stillness is the wrong picture. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 5 "Structure and Function of Plasma Membranes", section 5.2 Passive Transport_