What is a mixture?

A mixture is best defined as a combination of two or more substances that are not chemically combined. In this context, the components retain their individual properties and can be separated through physical means. For example, when you mix sand and salt, both substances remain distinct and can be separated by dissolution of salt in water, leaving sand behind.

This definition highlights the essential characteristic of mixtures: the substances maintain their chemical identities. Unlike compounds, which are formed when substances undergo a chemical reaction and lose their individual properties, mixtures allow for the original components to coexist without undergoing any chemical changes.

Furthermore, mixtures can vary in composition and can be homogeneous or heterogeneous, depending on how uniformly the components are mixed. A uniform solution of solute and solvent refers specifically to homogeneous mixtures, but not all mixtures are solutions. Therefore, the correct understanding of a mixture encompasses a broader scope than just solutions or compounds.