What we need to perform this activity is candles, glass water plate and matchsticks. So be careful while performing this experiment and have some adult supervision around.
Pour some water in the plate light the candle and you’ll see the candle floats. And when you cover it with the glass the, you’ll see that first the candle extinguishes because the oxygen inside is consumed and later the water rises. Isn’t this magical. You might think that the reason behind rising of the candle is that oxygen is getting consumed so there is a vacuum and water rises.
So let’s do this experiment with three matchsticks. By doing this we will heat the air inside to a much larger extent. And we will see the water rises way higher than before almost to half the height of the glass. The rise cannot be due to oxygen getting consumed as oxygen doesn’t make half of the air.
The rise is because the air gets heated up and then loses its heat to the glass and outside surroundings. Reduced temperature of air leads to lowering of its volume and hence the water rises inside. The more the heat more the water rises.