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give one reason to justify that air is a mixture.
- tiffany (age 16)
There are many ways to experimentally determine that air is a mixture of several different gasses, ranging from sophisticated laboratory spectral analysis to very simple experiments like putting a burning candle or a mouse in a closed container and observing that they eventually die because the oxygen is used up.
A Frenchman by the name of Lavoisier in the 1700's performed many experiments investigating the various constituents of air. Take a look at http://en.wikipedia.org/wiki/Antoine_Lavoisier
By the way, Monsieur Lavoisier got his head chopped off during the French revolution, largely because of his unpopular work as a tax collector under the old regime..
Another technique is to cool air down a lot. First ice will freeze out. Then a little dry ice may form. Then liquid oxygen will form, then liquid nitrogen. You can partially separate the different constituents this way.
(published on 04/29/2008)
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