Properties of Air – Explanation and Activity

Introduction

Air is the natural resource of the environment. Air is present all around us. We need Air for many purposes in daily life. Air is not only required for humans to breathe but animals and plants also need Air to live.

Since all-natural processes relate to Air, we cannot imagine life without Air. Although it is invisible, the presence of Air is felt in every activity in nature.

So let us learn about the Air and its properties in this session.

Explanation:

We might not have seen the Air, but its presence can feel it in several ways.

Air is present everywhere around us.

Activity: To show the Air is present everywhere.

Procedure:

1. Take a glass pot and fill it with water up to half.
2. Take an empty open bottle. Turn it upside down.
3. Sink the open mouth of the bottle into the container filled with water, as shown in the figure.
4. Observe the bottle.
5. Now tilt the bottle slightly.

Does Water Enter the Bottle?

Observation:

The bottle was not empty at all; Air was present in the bottle.

Originally, it was filled with Air even when we turned it upside down.

The water does not go into the bottle when upturned, as there was no space for Air to run away. When the bottle was tilted, the Air came out as bubbles, and water filled up the empty space that the Air had occupied.

Air helps to dry the clothes.

Air also helps to move sailboats and windmills.

Atmosphere:

A thin layer of air surrounds our earth.

This layer expands up too many kilometers above the surface of the earth and is called the atmosphere.

As we move higher in the atmosphere, the Air gets rarer.

Q: Why do mountaineers carry oxygen cylinders with them while climbing high mountains

Answer: As you climb to higher heights, the number of air decreases. And this lack of enough oxygen may cause suffocation to mountaineers when they reach high heights. So as a precaution, mountaineers usually carry oxygen cylinders with them.

Properties of Air:

1. Air is invisible.
2. Air is a matter
3. Air can be felt when it moves quickly.
4. Air has weight
5. Air exerts pressure.
6. Air can be compressed.

1. Air is Invisible.

We can feel Air around us. It can be seen or touched.

• It has no taste or smell.
• Air is transparent, which allows light to pass through it.
• The objects are seen clearly through Air.

2. Air Is a Matter, and Hence It Occupies Volume

Activity:

Procedure:

• Blow air into the empty balloon.
• The balloon will increase the size when air is blown into it as air has entered inside the balloon.

The same Air, when squeezed out of the balloon, can be felt on the hand, decreasing the size of the balloon.

3. Air Can Be Felt When It Moves Quickly

1. We can feel the Air when we stand in front of a working table fan.
2. When Air moves very fast, it is called wind.
3. We can feel the wind as it swings leaves on a tree, or during thunderstorms, the wind moves at a very high speed, even pulling up trees in its way.
4. Wind can move things with it.

4. Air has Weight

Activity:

Procedure:

1. Two identical balloons are taken, and one of them is filled with Air.
2. Both balloons are weighed separately.

Observation: The balloon with Air has more weight. This shows that Air has weight.

5. Air Exerts Pressure

Activity:

Procedure:

1. Take the empty can and fill it with water, and then heat it.
2. After some time, when it starts to convert into steam, the cap should be placed tightly so that steam cannot come out from the can.

Observation:

• The steam condenses, and the pressure inside the can also reduce as the steam reduces.
• The air out of the can exerts pressure and makes the can crumple.

6. Air can be Compressed.

Procedure: A leak-proof syringe, which is empty and filled with Air, is pushed towards the end.

Observation:

On pressing the piston of the syringe, a piston is moved inwards.

Conclusion: Air is highly compressible.

Importance of Air

1. We need Air to live and breathe.
2. Plants and animals also need Air for life.
3. If a plant is kept inside a closed jar, it is seen that it dies due to the absence of Air.
4. Animals also will die without Air.
5. Air is required for burning.

Conclusion:

This activity shows that Air occupies space. It is present everywhere around us.

1. What is filled in the balloon, tires, and swimming tubes?
2. How can the clothes dry?
3. How do the sailboats and windmills move?