14.air around us

•Air is present all around us.

•All living beings need air to breathe.

The wet clothes hanging under the sun become dry after some time.This is because the heat of the sun changes the water from these clothes into water vapour. Then,water vapour mixes with the air around.

This shows Air contains water vapour.

We can see dust when sun rays enter a dark room.

This shows Air contains dust and smoke also.

Smoke is given off when something burns and mixes with the air.

This shows Air contains smoke.

Germs from a sick person get mixed with the air when he sneezes or coughs.

This shows Air also contains germs.

Dust, smoke, and germs make the air dirty as it makes us ill.

Germs: A very small living being that can make you ill.

We must breathe in fresh and clean air.

It is important for good health.

Plants keep the air fresh ad clean.

We should grow green plants.

Take a deflated football and notice its shape and then fill air in it and observe the shape now.

Air has given shape to the blown up ball.

Air fills space.

Air gives shape to things.

Get a weighing machine.

Put the deflated ball on the machine first then fill air and put the blown up ball on the machine.

The ball with air in it will be heavier.

Air also has weight.

DEFLATED: To take the air out of something.

WIND:

Moving air is called wind.

Wind and air help us in many ways.

1. Wind helps a kity fly.

2. Wind helps a boat sail.

3. Wind helps clothes dry.

4. Wind helps a hang glider fly.

5. A parachute moves with the help of air.

6. Wind turns the blades of a windmill.

Imp: Did you know that the wind brings us the rainy weather?

A gentle wind is called a breeze.

We enjoy a cool breeze.

When wind is strong and blows very fast, it is called a storm.

A storm can be harmful. It can blow things away and can damage trees and houses.

A wind wane tells the direction of the wind. It is usually fixed on top of buildings. It is also known as a weather cock.