Simple Mixtures Very few substances occur in nature in pure form but are found instead to be in mixtures containing mulliple components. A mixture is a combination of two more substances each retaining their individual chemical and physical properties. Mixtures can be homogeneous or heterogeneous. A homogeneous mixt has spatially uniform composition and properties and are atso called solutions, whereas a heterogeneous mixture has components spatialy segregated : that the composition and properties vary throughout the mixture. If two substances can be combined all proportions to form a homogeneous mixture, they at said to be miscible. The tem is most commonly applied to liquids (e g. water and ethanol), but it can also be appied to gasses (e. 9 . oxygen and nitrogen) and solids (e.g. copper and zinc to make brass) Saltwater (liquid phase solution), clean air (gas phase solution), and alloys (solid phase sotution) are additional common examples of homogeneous mixtures. Dirt and chocolate chip cookes are common examples of heterogeneous maxtures