Mixture: a substance made by mixing other substances together physically.
Compound: made up or consisting of several parts or elements chemically.
Now that we understand their definitions we can justify and clarify that air is a mixture.
<span>The air is composed of many non-reactive gases such as nitrogen, hydrogen, methane, water vapor, carbon dioxide, etc. It can not be classified as a compound because compound means; several things (elements) compose a whole but chemically, and this previously mentioned gases are attached physically, not chemically.</span>
A compound has to be chemically bonded, however, air is not chemically bonded. This can be proven by freezing air. By freezing air, it yields different liquids at different temperature. Liquid nitrogen has a different boiling point than liquid oxygen. If air was a compound, they would all have a single boiling point and a single freezing point.
