EXISTENCE OF AIR
Air is around.
We breathe in oxygen and breathe out carbo dioxide.
Oxygen and carbon dioxide are air (gas).
All living things need air.
The human, animals and plants would die without air.
MEANING OF AIR
Air is the the mixture of gases that surround us.
The gases are invisible, odorless and tasteless.
When air is motion, it is called wind.
Wind is air in motion.
EXISTENCE OF AIR
Air exists because we breathe it everyday and it is necessary for all things living on this earth.
Apart from simple machines, other machines can not work perfectly without air.
For example – the car, generator, all air machines, pumping machine, etc.
ACTIVITIES ON EXISTENCE OF AIR
Materials – balloon, light ball, whistle, hand fan, rechargeable fan and musical instruments.
1. Gently breathe in and breathe out.
Breathing is the act of expelling air from the lungs.
2. Blow air in balloon, light ball, whistle or musical instruments.
ACTIVITIES ON PROPERTIES OF AIR
1. AIR HAS WEIGHT
Materials needed – Ball and scale balance
1. Weigh a deflated football bladder on a scale balance, take the weigh and write it down.
2. Inflate the football with air and weigh it again, take the weigh and write it down.
3. Compare the weights.
4. Which one is heavier?
5. What makes it heavier, if inflated ball is heavier?
6. What does this suggest to you?
Result(s) – Air has weight.
2. Air OCCUPIES SPACE
Materials needed – Bottles and buckets of water.
1. Put a small bottle upside down into a basin of water.
2. Turn the bottle up side down and put inside the water. What do you observe?
Result(s) – Water cannot go in the bottle.
3. Gently turn the mouth of the bottle toward the surface of the water. What do you observe?
Result(s) – Water can enter the bottle.
4. Explain why water cannot enter into the bottle in the first instance.
5. Is the bottle empty after? Result(s) – No, it is not empty.
Conclusion – Air occupies space.
For the water to enter the bottle, the air must go out.
But if the air cannot come out, water cannot enter.
3. AIR HAS PRESSURE
Materials needed – Balloons
1. Inflate a balloon.
2. Touch it gently.
3. How does it feel to touch.
4. Release the inflated balloon in front of pieces of paper.
5. What do you observe? Air blown the pieces of paper away.
Result(s) – Air can push anything about because it has weight and pressure.
The weight of an object is force that push objects about.
4. AIR HAS WEIGHT
Materials needed – Balloon and flat plywood
1. Inflated 4 balloons.
2. Put all the balloons together and place a flat plywood on them.
3. One of you should sit on it.
4. What do you observe?
5. What keeps the pupil afloat on the balloons?
Result(s) – Air has or support weight.
Bicycles, cars and lorries are resting on tyres containing a lot of air.
PROPERTIES OF AIR
The properties of air are as follows:
1. Air has weight.
2. Air occupies space.
3. Air exert pressure.
4. Air supports weight.
5. Air is affected by heat.
6. Air can be compressed.
7. Air is affected by altitude.
8. Air is made up of gases
IMPORTANCE (USES) OF AIR
The importance (uses) of air are as follows:
1. Air supports lives.
2. Air supports water cycle.
3. Air supports pollination.
4. Air helps in transport.
5. Air minimizes pollution.
6. Air regulates temperature.
Answer 7 questions including number 11.
1. say the different between oxygen and carbon dioxide.
2. demonstrate the existence of air.
3. state 5 things that produce air.
4. mention 5 living things that depends on air.
5. mention 5 machines that cannot work without air.
6. state 5 things contain air.
7. mention 5 animals that breathe in and out air.
8. plants breathe in and out air. True/False
9. identify 5 things that used air to work well. Hint – tyre, ball, balloon, etc.
10. state 5 uses of air.
11. Analyze how,
- air supports water cycle.
- air supports pollination.
- air regulates temperature.