sentence2_structure: Diffusion<>is<>the process in which a substance naturally moves from an area of higher to lower concentration$$$a substance<>naturally moves<>from an area of higher<>to lower concentration<>the process
sentence1: Diffusion is the movement of a substance from an area of greater concentration to an area of lesser concentration.
sentence2: Diffusion is the process in which a substance naturally moves from an area of higher to lower concentration.
question: What is the process in which a substance naturally moves from an area of higher to lower concentration called?