Final answer:
Substances will naturally diffuse from areas of higher concentration to areas of lower concentration along a concentration gradient.
Step-by-step explanation:
In the context of concentration gradients, if a concentration gradient is present, substances will naturally diffuse from higher concentrations to lower concentrations. Diffusion is a passive process of transport. It involves the movement of substances across a gradient. This process tends to move substances from an area where they are in high concentration to areas where they are in low concentration. Think of opening a bottle of ammonia in a room: the ammonia gas will spread from the bottle, where its concentration is high, to the rest of the room, where its concentration is lower. This movement continues until equilibrium is reached, meaning the substance is evenly distributed through the space.