What is defined as a stable physical mixture of two or more substances?

A stable physical mixture of two or more substances is defined as a solution. In a solution, one substance, known as the solute, is fully dissolved in another substance, known as the solvent, creating a homogeneous mixture. This means that the individual components cannot be identified separately and the mixture appears uniform throughout.

Solutions are characterized by their clarity and the inability to scatter light, which distinguishes them from other types of mixtures. In contrast to solutions, suspensions consist of larger particles that can settle over time, while colloids contain intermediate-sized particles that remain evenly dispersed but may scatter light. An emulsion is a specific type of colloid involving the mixing of two immiscible liquids, often requiring an emulsifying agent to maintain stability. Thus, a solution is the most appropriate term for describing a stable mixture where the solute is uniformly distributed within the solvent.