Brass is a homogeneous mixture of copper and zinc in which the concentration of zinc and copper is the same throughout the entire mixture. Brass is an example of a solid homogeneous mixture. This type of mixture also occurs in gas and liquid forms.
An example of a gaseous homogeneous mixture is air. Air is made up of nitrogen dioxide (N2), oxygen dioxide (O2), water (H20), and carbon dioxide (CO2). On their own, each of these gases, as well as the solids of zinc and copper, are known as pure substances. Only when they are uniformly mixed do they create a homogeneous mixture. An example of a liquid homogeneous mixture would be beer, which is made up of water and ethanol.