Air

Air is a non-specific name for atmosphere used in breathing and photosynthesis, in particular to the dry air (containing, by volume, roughly 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases) used by humans and other living organisms on Earth.

In certain symbolic contexts, air is one of the four classical Aristotelian elements.