Air - Composition, Properties, Olympiad Questions, etc.

What is Air?

a) Air is all around us. We can't see it, but we can feel it when it moves.
b) Air is the substance we breathe in and out.
c) Air is made up of tiny particles, which are so small that we can't see them with our eyes.

Composition of Air

Air is made up of a composition of different gases mixed together. These are:

a) Nitrogen: The main gas in the air is nitrogen. It makes up about 78% of the air.
b) Oxygen: Another important gas in the air is oxygen. It makes up about 21% of the air. Oxygen is what our bodies need to live.
c) Carbon dioxide: The amount of carbon dioxide in the air is only 0.04% but it is very important for plants.
d) Others: The rest of the air is made up of some other gases and water vapours.

Here is a pie chart diagram of the composition of air.

Properties of Air

a) Air is invisible, which means we can't see it with our eyes.
b) Air has mass.
c) Air can flow, move around freely, and fill up spaces.
d) Air can make things move.
e) Air is essential for living things like us. Without air, we won’t be able to live.
f) Air is colourless and odourless.
g) Air may feel light compared to solid objects, but it has weight.

Activities that Need Air

Air has many important uses in our everyday lives. Some of them are:

a) We use air to breathe.
b) Air helps things like kites fly by making them float or glide through the air.
c) Air helps us make sounds when we talk, sing, or play musical instruments like flutes.
d) Air can make wet things dry.
e) Air can move things. For example, blowing air on a sail helps the boat move in the water.
f) Air is essential to make fire. Without oxygen present in the air, we cannot light a fire.
g) Aeroplanes use air to lift off the ground and fly people and things to different places around the world.
h) Air is used to inflate tires and balloons.

Air Pollution

a) Air pollution happens when harmful substances get into the air and make it unhealthy for us to breathe.
b) These substances such as harmful smoke, chemicals, and gases can be released into the air from factories, cars, or even things we use in our homes.
c) When we breathe in polluted air, it can make us sick and cause problems like coughing, sneezing, or even difficulty in breathing.
d) Some pollutants in the air can also harm plants and animals.