In a solution, what is the term for the substance that is dissolved?

In a solution, the term used to refer to the substance that is dissolved is "solute." This is the component of the solution that is present in a lesser amount compared to the solvent, which is the substance that does the dissolving. When you mix a solute with a solvent, the solute breaks down into smaller particles and becomes evenly distributed within the solvent, resulting in a homogeneous mixture.

The concept of solutes is essential in understanding various scientific processes, such as chemical reactions in aqueous solutions, where the behavior of solutes can significantly affect reaction rates and outcomes. For example, in a saltwater solution, salt is the solute that dissolves in the water, which acts as the solvent.

Other terms in the list, such as "mixture" and "colloid," refer to broader categories of combinations of substances and do not specifically identify the dissolved component of a solution. A colloid, for instance, is a type of mixture where small particles of one substance are dispersed throughout another, but these particles do not necessarily dissolve in the solvent as a solute does.