What is the term used when substances are dissolved in one another and will not settle out?

The term that describes substances dissolved in one another that will not settle out is a solution. In a solution, the solute (the substance being dissolved) is evenly distributed within the solvent (the substance doing the dissolving), creating a homogeneous mixture. Because the particles in a solution are at a molecular or ionic level, they remain uniformly suspended without separating over time.

This differential ability to maintain a stable mixture distinguishes solutions from other types of mixtures, such as suspensions and colloids. In suspensions, larger particles can settle out over time, while in colloids, particle size is intermediate and may not settle under gravity, but they can scatter light. A compound, on the other hand, refers to a substance formed when two or more elements chemically bond in specific proportions, which is different from the mere physical combination found in solutions. Therefore, solution is the most accurate term for describing substances dissolved in one another that do not settle out.