Carbon Dioxide - the enemy of fire !

Carbon Dioxide - the enemy of fire

How can you prove that Carbon Dioxide is extinguishes fire.
Here is a simple experiment which will help us to solve the mystery.

First of all we require following materials namely:

A bottle, a glass bowl, vinegar, washing soda, three candles of different sizes(lengths), thick paper sheet, pair of scissors, glue and a round stick.

Now proceed:-

Can you prove that carbon dioxide is heavier than air and fire cannot be lighted in its presence? Well, we shall tell you how to perform this simple experiment. Now fill half of the bottle with vinegar and drop some washing soda in it. Soon you'll notice that bubbles start forming in the liquid and          carbon dioxide emerges out of it. Put shorter end of the paper tube in bottle's mouth and the other on the edge of the glass bowl. Now light three candles of different lengths in it.

First of all, make a narrow tube of paper whose diameter should be a little smaller than bottle's mouth. You can do this by wrapping it on a stick or wand of the desired size, and sticking the paper with glue.
Once the gum is dry, you can slip off the stick and bend one third of the paper tube, as shown in the
figure.
What happens now? The carbon dioxide that is produced in the  bottle starts settling in the glass bowl. And as its level rises and reaches the smallest candle, it extinguishes that candle. On one hand the bubbles are constantly produced in the bottle and on the other its level keeps on rising. Its effect on the other candles can be observed visibly.
All this just goes to prove that the carbon dioxide gas is heavier than air, and fire cannot be lighted in its Presence.