Definition of Air

Air is something we humans breathe and live within. We understand it to be a part of our natural existence and daily right. Having and inhabiting air is as natural to us as well, breathing.

But, what is air? What is its components and how does it act in our atmosphere?

Air surrounds the earth in a mixture of gases. It is invisible and odorless. The area of our atmosphere that contains the gases that make up what we call air rises approximately 400 miles above the earth. This is named the lower atmosphere. Going higher up, we encounter the troposphere which is between 30,000-50,000 ft. The stratosphere ranges from 50,000ft to 200 miles. The ionosphere rises to the highest levels between 200-400 miles.

Chemical Components

Air is made up of a combination of gases and moisture levels. These gases make it possible for us to live and breath while here on the planet and can seriously impact our health if the gases are missing or other gases are introduced to the mix.


The question, what is air cannot be answered without including this most important element. Approximately 23% of the atmosphere is made up of this highly important gas. This gas is created by plants that give it off as a process of photosynthesis.


Nitrogen is unstable and does not readily combine with other things. Approximately 75% of the earth’s atmoshere contains nitrogen. It can be combined with hydrogen to produce ammonia and refrigerants.

Carbon Dioxide(CO2)

This gas makes up .03%-.04% of the atmosphere and is a combination of carbon and oxygen. It is important because it is necessary for plant life.


This gas is so light it doesn’t appear in the atmosphere as a percentage. It is most often seen in the water molecule as a necessary ingredient for its creation.

Sulfur Dioxide(SO2)

This gas is a contaminant in our air and is created as a byproduct of a gaseous combustion processes.

Water Vapor

Moisture or humidity is contained within molecules of air. This moisture impacts levels of static electricity, comfortable living, and is expresses as relative humidity.

Rare Gases

The rare gases to be found in our air are xenon, krypton, helium, argon and neon. They are present from .9%-1.3% of the atmosphere.

Xenon-(Xe) This is a chemical element that is odorless and colorless. It is mostly unreactive and can be used in arc lamps and as an anesthetic. It is also used to propel ion thrusters in spacecraft.

Krypton(Kr) This gas is odorless, colorless and tasteless. It can be combined with other gases to be used in fluorescent lamps, lasers, and areas of photography.

Helium(He) This gas is non toxic, inert and presents as odorless, tasteless and colorless. It is the second most available gas present in the atmosphere behind hydrogen. It can be produced as the result of nuclear fusion. It is found in natural gas reserves here in the USA making us the largest supplier of it.

Argon(Ar) This chemical element is the third most abundant gas in our atmosphere and is also part of the earth’s crust. It is employed as a shielding gas in welding, flourescent lighting, and glow starters.

Neon(Ne) This element is also colorless and odorless. It is the fifth most often found element in our atmosphere and gives off a red/orange glow. It is used in lasers, plasma tube and refrigerant applications.

These are the elements and components that make up our atmosphere. It is a delicate and precise combination of gases that keep our atmosphere balanced and provide for us the necessary things we need to survive and thrive.