Classify each of the following as a pure substance, a solution, or a heterogeneous mixture: (c) stainless steel.

Key Concepts

Pure Substance

A pure substance consists of a single type of particle and has a uniform and definite composition. It can be an element, like gold, or a compound, like water. Pure substances have consistent properties throughout, such as boiling and melting points, which do not change regardless of the sample size.

Solution

A solution is a homogeneous mixture where one substance (the solute) is dissolved in another (the solvent). Solutions have a uniform composition and properties throughout, meaning that any sample taken from the solution will have the same ratio of solute to solvent. Common examples include saltwater and sugar dissolved in tea.

Heterogeneous Mixture

A heterogeneous mixture contains two or more substances that remain physically separate and can be distinguished from one another. The composition is not uniform, and different samples may have different proportions of the components. Examples include salad, sand and salt mixture, or a bowl of mixed nuts.