Soil is considered a mixture, as it is a composition in which each of the components retains its own properties. Mixtures have no fixed chemical structure or composition, and each of the atoms or molecules can be physically separated from one another as they have not undergone a chemical change.
Other examples of mixtures include air and sea water. Air is a mixture because it contains numerous different gases that can be physically separated from one another. On the other hand, pure oxygen gas is a compound, as it always consists of two oxygen atoms that are chemically bonded together.