The state in which a substance has spread out so there is no net movement is called:

1. Diffusion continues until a substance is evenly spread. 2. Individual molecules keep moving even then, so nothing is truly still. 3. This lack of a concentration gradient in which there is no net movement of a substance is known as dynamic equilibrium. 4. Osmotic pressure describes a force, not this end state. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 5 'Structure and Function of Plasma Membranes', sections 5.1-5.4_