What is a mixture of two or more substances called when a solid, liquid, or gaseous substance is dissolved in another substance?

The term for a mixture of two or more substances, where a solid, liquid, or gaseous substance is dissolved in another substance, is known as a solution. A solution is characterized by the uniform distribution of the dissolved substance throughout the solvent, creating a single phase. For example, when salt is dissolved in water, the salt particles disperse uniformly, making it impossible to distinguish between the salt and the water; they exist together as one homogeneous mixture.

In contrast, a colloid is a mixture where microscopic particles of one substance are evenly dispersed in another but are not completely dissolved, resulting in a mixture that can exhibit properties such as scattering light. A suspension consists of larger particles that are dispersed throughout a liquid or gas but will eventually settle out if left undisturbed. An emulsion is a specific type of colloid, involving the mixing of two liquids that do not typically mix, such as oil and water, with the help of an emulsifying agent.

Understanding the distinctions among these terms is crucial in barbering and cosmetic applications, as the properties of different mixtures impact their use in products or treatments applied during service.