A pure substance is a material that is composed of only one type of atom or molecule. Examples of pure substances include elements such as gold, oxygen, and nitrogen, as well as compounds such as water, carbon dioxide, and table salt.
A mixture is a material composed of two or more different substances that are not chemically combined. Examples of mixtures include air, which is composed of different gases, and soil, which is composed of various minerals, organic matter, and water.
mixchers, micschers