Oxygen in air is a gas used by all the human beings and animals to breathe. About one-fifth (1/5) of the air is oxygen. That means there is about 21% of the oxygen in air.
How does the environment get oxygen?
Green plants release (give out) oxygen as a waste product in sunlight when they produce their food.
An experiment to show that the green plants give out oxygen in sunlight.
- A waterweed
- A beaker
- A funnel
- A test tube
- Water
- This experiment should be done on a sunny day.
- Put a waterweed in a beaker.
- Put a funnel on the waterweed and a test tube full with water on it.
- Keep it under the bright sun for about 30 minutes.
- After 30 minutes you can see water in the test tube has gone down.Reason: When oxygen is released, it will enter the test tube and the water will go down.
- When the test tube is filled with oxygen you can insert (put in) a dimmed match.
Reason: If the test tube is really filled with oxygen the dimmed match should take fire again.
Conclusion:
Green plants give out oxygen in sunlight.
- Humans and other animals need oxygen to breathe.
- Divers working underwater need oxygen to breathe so they carry oxygen in bottles on their back.
- Astronauts (A person trained to travel in a spacecraft) take all their oxygen with them.
- Firefighters carry bottles of oxygen when they put out very smoky fires.
- When people are very ill, doctors give them oxygen to breathe.
- Fires need oxygen to burn.
- Oxygen is mixed with a gas called ‘acetylene’ and this forms a flame called, ‘Oxyacetylene’. The flame Oxyacetylene is used to weld (join) metals such as iron and steel.
- Oxygen is used to burn the fuel in spacecrafts.
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Written By : admin
8:43 am