The permanent gases whose percentages do not change from day to day are nitrogen, oxygen and argon. Nitrogen accounts for 78% of the atmosphere, oxygen 21% and argon 0.9%. Gases like carbon dioxide, nitrous oxides, methane, and ozone are trace gases that account for about a tenth of one percent of the atmosphere.

Nitrogen and oxygen are by far the most common; dry air is composed of about 78% nitrogen (N2) and about 21% oxygen (O2). Argon, carbon dioxide (CO2), and many other gases are also present in much lower amounts; each makes up less than 1% of the atmosphere’s mixture of gases.

Nitrogen and oxygen account for 99 percent of the gases in dry air, with argon, carbon dioxide, helium, neon, and other gases making up minute portions.

The lowest level consists mainly of molecular nitrogen (N2). Above it, there is a layer of atomic oxygen (O). At an even higher altitude, helium atoms (He) are the most abundant element. “The 4 Most Abundant Gases in Earth’s Atmosphere.” ThoughtCo, Aug.

Some references include other gases on this list, such as krypton (less abundant than helium, but more than hydrogen), xenon (less abundant than hydrogen), nitrogen dioxide (less abundant than ozone), and iodine (less abundant than ozone).

The air in Earth’s atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of lots of other gases, too, such as carbon dioxide, neon, and hydrogen.

Technically yes, relative to an observer on Earth, a person at higher altitudes will age faster.

about 20,000 feet

It refers to altitudes above a certain point where the amount of oxygen is insufficient to sustain human life for an extended time span. This point is generally tagged as 8,000 m (26,000 ft, less than 356 millibars of atmospheric pressure).