Experiment: To make a cloud in a bottle.

Materials:

You will need:

A 2 - 5 litre plastic bottle (clear and without the label) with lid
1 box of matches
Warm Water

 

Method:

What you have to do: 

1) Put the bottle on to a solid surface and pour warm water into it - to about a third of the way.

2) Light two matches together to add some smoke to the bottle. The smoke represents dust that must be present if a cloud is to form. Drop the lit matches into the opening at the top of the bottle. Quickly close the lid.

3) If it is difficult to see the contents of the bottle with condensation, shake it to make it clearer.

4) Now squeeze the bottle to increase the pressure - then release it.

Result: When the pressure is released, a cloud quickly forms in your bottle.

Conclusion: To make a cloud, you need three things - dust, water vapour and low pressure. The warm water produces water vapour, and the smoke from the match acts as dust. The low pressure is formed by first squeezing and then letting go of the bottle.