A fellow student does not understand why air is a mixture. Write a brief explanation about why air is a mixture, whether it is homogeneous or heterogeneous, and how it can be separated.

Air contains roughly 78% nitrogen, 21% oxygen, and the last 1% is other gases like CO2 and argon. air is homogeneous. the components of air can be separated through cooling until they liquidfy then through distilaltion can they be separated into pure substances.