One very important gas is oxygen. It is produced by plants during a process called photosynthesis. In this natural chemical reaction carbon dioxide molecules are combined with water molecules to produce a sugar molecule and oxygen gas.
This reaction is written as a chemical equation.

Oxygen can be produced in the laboratory using hydrogen peroxide and manganese dioxide. Click to see how oxygen supports combustion.

Click the picture above to see the movie of oxygen supporting combustion. Notice the amount of energy that is released as a glowing splint is placed in pure oxygen.

What this says is that 6 carbon dioxide molecules react with 6 water molecules to produce 6 oxygen molecules and 1 sugar molecule.
Oxygen can be produced in the laboratory by reacting manganese dioxide with hydrogen peroxide.
Oxygen is important to all life.
Most life forms use oxygen to burn
the food in their bodies. Burning
food releases energy which is then
used by the organism to sustain life.



Look at the reaction of photosynthesis. Explain how we could not survive without massive forests on Earth.

Explain how we are creating a very dangerous situation when we cut down forests and increase the amount of cars on our roads. Hint - look at the products formed when petrol burns with oxygen..

We pour water onto fire to extinguish it. How does the water put out the fire?

Run the movie of oxygen supporting combustion.. Why is oxygen necessary for fuels to burn?
Hint- look at the energy released.


Continue with an acitvity