In the field of chemistry, a mixture simply refers to the type of material system which is composed of two or more substances that are mixed together, but are not chemically combined. Basically, a mixture is only the physical combination of substances, and may come in the form of suspensions, colloids, or solutions.

A mixture can be produced by mechanically combining or mixing together substances, such as elements or compounds to form a single product. It is important to note that because the creation of a mixture does not involve any chemical changes or chemical bonding, each of the substances that were mixed together retains its own identity, chemical structure, and properties. However, although there are no chemical changes involved, some properties including the melting point may be different from that of the individual substances.

There are some types of mixtures wherein the components can easily be separated through physical or mechanical methods. However, there are some types of mixtures which can be considerably difficult to separate into its constituents. One example of this type of mixture includes azeotropes.

There are two types of mixtures, and these are heterogeneous and homogeneous. A homogeneous mixture refers to the type which can be characterized by a uniform composition, and each component of the solution has similar properties. An example of a homogeneous mixture includes air, which is made up of oxygen, nitrogen, and other gases. There are some substances such as salt and sugar, which can also be dissolved in water or other liquids to produce a homogeneous mixture. Generally, homogeneous mixtures that are composed of a solvent and a solute is also called a solution.

On the other hand, a heterogeneous mixture refers to the type which have parts that can be seen separately. Some examples of heterogeneous mixtures include sand and iron filings, water and oil, sand and water, salads, gold and silver in powder form, and conglomerate rock.