Air Composition Properties - Chemical Composition of Air, FAQs

In this article we will be discussing about the composition of air, properties of air/characteristics of air, atmospheric air composition, gases in air or air content, What are the properties of air and what is not a property of air.
Meaning of air
Air is the invisible gaseous substance that surrounds the earth, it is mainly a mixture of oxygen and nitrogen.

Meaning of air in Hindi is वायु

We know that matter occupies space. Air is also a matter and it is essential for our lives. Our planet Earth is covered by a blanket like layer called the Atmosphere. Among all the other fundamental elements present in the nature, it is the vital because live cannot exists without air. So now let’s discuss about the composition of air.

Also read -

• NCERT Solutions for Class 11 Physics
• NCERT Solutions for Class 12 Physics
• NCERT Solutions for All Subjects

Chemical composition of air or Chemical composition of atmosphere

Composition of air by mass: Earth’s atmosphere consists of a mixture of gases called the air. The gases are usually odourless and colourless. As a result, we cannot touch or see the air. We can only feel the air. The earth’s atmosphere consists of 78% of Nitrogen, 21% of oxygen, 0.93% of Argon, 0.04% of Carbon dioxide, and traces of helium, methane, neon, krypton and hydrogen, as well as water vapour.

The composition of air remains same upto to a height of approximately 10,000 m.

Other composition of air/atmospheric air composition

Some other composition of air are as follows:-

Sulphur dioxide(1.0ppm), Methane(2.0ppm), Nitrous oxide(0.5ppm), Ozone(0 to 0.07ppm), Nitrogen dioxide(0.02ppm), Iodine(0.01ppm), Carbon monoxide(0 to trace ppm), and Ammonia(0 to trace ppm).

Describe the Composition of air

Let us describe the Composition of air, one by one:

Here are the main gases in air.

• Nitrogen

Nitrogen is the major component that is found in air. It is the most abundant gas present on the earth. It is required for the growth of plants and animals. Nitrogen composition in the air is 78%.

• Oxygen

Composition of Oxygen in air is 21% (approximately). Oxygen is required by all living organisms because they derive energy from food with the help of oxygen.

• Carbon dioxide

Carbon dioxide occupies a small content of air around us. It is essential for plants and animals. Plants utilise carbon dioxide to make food during photosynthesis. The process of photosynthesis and respiration helps in maintaining the balance of oxygen and carbon dioxide in the atmosphere.

What are the properties of air?

Some of the properties of air/characteristics of air are as follows:-

1. Air occupies space.
2. Air has mass.
3. Heat affect the air.
4. Air exerts pressure.
5. Air is compressible.
6. Altitude affects air.

These properties are so easy to remember even for kids. Therefore, we can say that we have mentioned the properties of air for kids. Properties of air pdf includes all these major points.

Now, as we discuss further about the properties of air, a question arises that Air shows the properties of both oxygen and nitrogen. Why? The answer to this question is air shows the properties of both oxygen and nitrogen because air is a mixture of gases. That’s why it will show the property of both oxygen and nitrogen present in it.

Q. Which is not a property of air among the following options. (a)Air has mass. (b) Air occupies space. (c) Air is compressible. (d) Air is a compound.

Ans. (d) Air is a compound.

Air Properties Table/Properties of air worksheet

Properties of air experiments

1. Let’s take an empty glass bottle. Now, put the open mouth of the bottle into a container filled with water. It is observed that water does not enter the bottle when it is in an inverted position, as there is no space for air to escape. This shows that air occupies space.
2. Let’s hang two balloons at the end of a thin straw. If we one balloon is burst then the straw will move towards the balloon that is left. This shows that air has mass.

NCERT Physics Notes :

• NCERT Notes class 11 physics
• NCERT Notes class 12 physics
• NCERT Notes for all subject

Gases in Air

Composition of gases in air: Nitrogen (N2 ) is the most abundant occurring natural gas, and it makes up about 78% of air. The second most abundant gas is oxygen and it is about 21%. Argon (Ar), the inert gas is the third most abundant gas at 0.93%. Some other gases like carbon dioxide (CO2), nitrous oxide (NO),neon (Ne), krypton (Kr), helium (He), methane (CH4), hydrogen (H2), xenon (Xe), ozone (O3), iodine (I2), carbon monoxide (CO), and ammonia (NH3), etc. are also present in the atmosphere.

Does air occupy space?

Or

How will you prove that air occupies space?

Let’s take an empty glass bottle. Now, put the open mouth of the bottle into a container filled with water. It is observed that water does not enter the bottle when it in an inverted position, as there is no space for air to escape. This shows that air occupies space.

Air occupies space examples

Let’s take a balloon and fill it up. The air from ours lungs enters the balloons and it expands because air inside it is taking up the space.

Also read :

NCERT Solutions for Class 6 Science Chapter 15 - Air Around Us

Q. Why we can’t see air?

We can’t see air because it sends very little colour to our eyes. We see objects because they absorb some light wavelengths, and reflect others back to us. Objects appear to be the colour they reflect to our eyes.

We know that air is a mixture of gases and every gas has different wavelengths. When the light bump a molecule, it absorbs some colour and then reflect it back. The reflected light enters our eye and then we are able to see the object. But in case of air, wavelengths of light may pass by the molecules without hitting them.

When they do bump a molecule, it absorbs some colour and scatters some, spreading it out in all directions. Too little light reaches our eyes for us to notice. That’s why we can’t see air.

Physical Properties for Air

Also check-

• NCERT Exemplar Class 11th Physics Solutions
• NCERT Exemplar Class 12th Physics Solutions
• NCERT Exemplar Solutions for All Subjects