Ishita, our Director of Delhi Chapter, demonstrated Charle's Law to 4th and 5th grade students of MCD (Minicipal Corporation of Delhi) School, Phase 2, Ashok Vihar, Delhi. About 55 students with their respective teachers attended the demo. She started with rising water experiment, following with steps as below:
Filled a shallow dish with colored water to cover the bottom only
Placed the candle/votive in the middle of the dish
Lighted the candle and quickly covered with the glass
Students observed the water rising in the glass as the candle burnt out
Students were asked to deliberate as to what happened, and they participated very actively and enthusiastically. The responses received from the students were narrowed down to give a clear and deep understanding of the phenomenon. It was conclusively explained by Ishita that after burning out of candle, the temperature decreases, and thus the volume decreases, which lets the water rise to fill up the space in the glass.
Charles Law - Volume of a gas is directly proportional to the temperature of the gas. Some of the examples discussed by Ishita were:
a) A soda bottle has more fizz in summer
b) Difference in the volume of a cake batter before and after being put into the oven
c) A football contracts in winters due to temperature
d) Hot air balloon mechanism
e) Cracking of perfume bottle if kept in heat
Other examples sought from the students were about Helium balloons and the like. It was encouraging to note that the session ended in a happy and congenial note with students participating actively and willing to take more of such activities. The activity was coordinated by the Co-ordinator, Mrs. Charvi and facilitated by the Mrs Yogita, Head of the school and the respective staff.
