What term refers to a mixture with one substance spread evenly throughout another?

The term that refers to a mixture with one substance spread evenly throughout another is a solution. In a solution, the solute (the substance being dissolved) is completely dissolved in the solvent (the substance in which the solute is dissolved), resulting in a homogeneous mixture where the composition is uniform throughout.

This is important in many scientific and practical contexts; for example, when salt is dissolved in water, it forms a solution that appears to be a single liquid rather than having distinct parts. This uniformity allows for consistent properties throughout the mixture.

In contrast, other terms describe different types of mixtures. A suspension consists of solid particles that are not completely dissolved and can settle over time. A colloid contains larger particles than those in a solution but are still small enough to remain evenly distributed, while an emulsion specifically refers to a mixture of two immiscible liquids that do not blend easily, like oil and water. Understanding these distinctions helps clarify why a solution is characterized by complete and even distribution of one substance throughout another.