Components of Air


John Mayow, the English physician of 1674 discovered that air is not a single element, it is a mixture of different kinds of gases. The discovery made by scientists is wide to get a clear idea about the composition of air. Joseph Priestley, a chemist 1774 discovered the presence of Oxygen in the air. Joseph Black, a chemist of 1750 discovered the presence of Carbon dioxide in the air. Noxious air, now known as Nitrogen gas, was discovered by Daniel Rutherford in 1772.

Henry Cavendish in 1785 was not satisfied with the components present in the air since 0.7% of air is missing by some unknown component. He made several experiments for its discovery but only 100 years later scientists confirmed that it is a less reactive Argon compound that they missed. William Ramsay in 1894, discovered the Argon gas in the air.

What are the Components of Air?

Air is a combination of several gases. The main components of air are Nitrogen, Oxygen, and Argon. In addition to these gases, there are some other gases also present in the atmosphere. But they are in less composition compared to these gases. The supreme component of air is the gas Nitrogen. About 78% of Earth's atmosphere consists of nitrogen gas. And other gases such as Oxygen contribute about 21% and 0.9% by Argon. In addition to these gases, some trace gases are also present. They are all mainly noble gases or inert gases such as Xenon, Krypton, Helium, and also some other gases such as Hydrogen, Ozone, and Methane. The composition of gases present in the air changes with changing locations and also varies with climate.

In addition to these gases, air contains some amount of water vapour too but it varies with changing environment, an average amount of water content in the air is 0.25%. Humid air contains water droplets too. However, these are all naturally made components. But there are some man-made pollutants too. And these are toxic and cause air pollution.

Composition of Air

Earth's atmosphere is fully covered with a wide variety of gases. But these gases are colourless and odourless, we cannot see them using our naked eyes. The percentage of components present in the air does not vary but what varies by different location is the number of molecules of gases. The water content varies in different locations and is due to the changing temperature. Temperature decreases by about 0.6°C on moving 100m height across the atmosphere. Almost all the location's percentage composition of air alike. The composition of air is tabulated below with its average values.

Nitrogen, $\mathrm{N_{2}}$ 78.1%
Oxygen, $\mathrm{O_{2}}$ 20.9%
Argon, Ar 0.925%
Carbon dioxide, $\mathrm{CO_{2}}$ 0.04%
Neon, Ne 0.018%
Helium, He 0.000521%
Methane, $\mathrm{CH_{4}}$ 0.00018%
Krypton, Kr 0.00012%
Hydrogen, $\mathrm{H_{2}}$ 0.000055%
Nitrous oxide, $\mathrm{N_{2}O}$ 0.0000321%
Carbon monoxide, 𝐶𝑂 0.00002%
Xenon, Xe 0.0000087%
Nitrogen dioxide, $\mathrm{NO_{2}}$ 0.000002%

In addition to these prominent species, some other components are also present. And they are listed below.

Gases Composition
Sulfur dioxide, $\mathrm{SO_{2}}$ 0.0000001%
Iodine, $\mathrm{I_{2}}$ 0.01ppm
Ozone, $\mathrm{O_{3}}$ 0.07ppm
Ammonia, $\mathrm{NH_{3}}$ 0.000001%

Main Components of Air

The Components of air play an important role in the existence of life on Earth. The presence of gases in the air makes animals and plants breathe. Also protects from unwanted UV radiations coming from the sun. So their role of them is very wide. The working of these gases only takes place when it is present in the right amount. If no right amount is present it may cause some problems too. The place where they are located also plays a good role. If Ozone comes to the surface of the atmosphere it will be a toxic compound for living organisms.

The main components present in the atmosphere make it important. Among the constituents of air, the most prominent one is Nitrogen(78%). It is an important naturally occurring element for the growth and reproduction of plants and animals. The next important one is Oxygen(20.9%).

As we all know Oxygen is an essential component of the existence of life. Without Oxygen, life will longer persist. Even though about a huge proportion of air has been taken by these elements(98.9%), there are some other species in a comparatively small amount too. Of which the primary one is Argon(0.9%).

It doesn't mean that the only components are Nitrogen and Oxygen, as air is a vast thing this composition is itself a higher amount. As a whole, the major components are Nitrogen, Oxygen, and Argon. And also some other gases such as Carbon dioxide, Carbon monoxide, Nitrogen dioxide, Helium, Hydrogen, etc.


Air is what surrounds us. It is a mixture of different cases. Even though the composition of gases present in the atmosphere does not make any sense. But is an important value since air is a vast thing. Scientists have made different experiments to get a clear idea about the gases present in the atmosphere. It has been expanded with the evolution of more instruments discovered by scientists. The role of these gases is also very important. Since these gases are responsible for the existence of life on Earth. The major contribution of gases present in the air is Nitrogen. Then comes the Oxygen and then Argon. In addition to these major components, some amounts of other gases are also present such as Hydrogen, Helium, Carbon dioxide, etc.


1. What are the different layers of Earth's atmosphere?

There are 5 layers of the atmosphere. Starting from the bottom the first one is the Troposphere(0-10Km). Most of the games are present in this layer. Such as Nitrogen, Oxygen, etc. Then comes the Stratosphere (10-30Km). The gas found in this layer is Ozone. Then the Mesosphere (30-50Km). The percentage of gases is the same as the Troposphere but contains some water vapour too. Then the Thermosphere (50- 400Km). In this layer, gases are found in atomic form. And the last one is Exosphere (above 400Km). Gases such as Helium, Hydrogen, etc in extremely fewer amounts are found in this layer.

2. What are greenhouse gases?

The gases that can absorb infrared radiations coming from the sun are greenhouse gases. They are Carbon dioxide, Methane, and Chlorofluorocarbons. And the process of this heat absorption and thereby making our Earth warm is the greenhouse effect.

3. What is global warming?

The rise in temperature due to the extensive release of greenhouse gases in the atmosphere is global warming. The burning of fuel releases a large amount of Carbon dioxide into the atmosphere. And this will makes our planet raise the temperature. This phenomenon occurs due to human intervention.

4. What are the 4 properties of air?

  • It will take space to occupy.

  • It has a quantity.

  • It can be condensed.

  • It will exert pressure.

5. What are the two main categories of air?

There are two kinds of air. The initial one is dry air. As the name itself depicts the percentage of moisture or water vapour is very low which is less than 1%. And the other one is moist or wet air. For this category the presence of water vapour or moisture is high.

Updated on: 29-Jan-2024
Kickstart Your Career

Get certified by completing the course

Get Started