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What gas makes up the greatest percentage of the air we breathe?
Air is mostly made up of Nitrogen gas (about 75%). The
other biggie is Oxygen gas (about 20%). The last little bit is a
mixture of argon, water, carbon dioxide, ozone, and others. For more
information on why this is, check out the answer to the question Why is there so much nitrogen?
(published on 10/22/2007)
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