Air that Rises

AsSalyamu `Aleykum wa RahmatuLlahi wa Barakatuh,

Equipment: bottle with two holes in the lid, plastic tube, cooking oil

1. Pour oil into the bottle so it almost reaches the top. Seal it with the lid. Push a tube into the bottle, so that it reaches the bottom of the bottle.

2. Blow into the tube in order to make an air bubble. (but be gentle - I did first time and oil went all over my dress)

3. Watch the air bubble carefully as it rises along the test tube. The bubble gets bigger and bigger as it rises. The same happens to the air in the atmosphere. This causes the air to cool.