Air is matter that has weight and contains 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of argon, carbon dioxide and other ingredients.Know More
Air is a mixture of gases, which is why it has weight. Gases are a composition of several molecules that remain in constant motion. It occupies volume in space, but how much space it takes up depends on its temperature. Normally, gases at a higher temperature take up more space.
Air's density varies in different parts of the atmosphere. At the edge of space, its density is zero. Air density, temperature and pressure can change several times per day and varies from region to region.Learn more about Atmosphere
While the composition of dry air differs slightly from place to place, it is generally made up of about 78 percent nitrogen and 21 percent oxygen. Argon makes up most of the remaining 1 percent, and carbon dioxide and other trace elements make up the rest.Full Answer >
The air that people breathe is almost identical to atmospheric air, consisting of about 78 percent nitrogen and 21 percent oxygen. The last 1 percent of air composition is made of several different gases like argon, helium, carbon dioxide, methane, hydrogen and water vapor.Full Answer >
Air is a mixture, not a compound. Scientists define a mixture as a heterogeneous blend of molecules and atoms in variable proportions, while a compound is a substance formed by the chemical combination of two or more elements in fixed proportions.Full Answer >
Air seems thinner at high altitudes because air pressure is lower, which allows individual air molecules to occupy a larger volume than air molecules do at low altitudes. This decreasing pressure with increasing altitude occurs because there are increasingly fewer air molecules exerting pressure on the next-lowest altitude.Full Answer >