Tuesday 10 January 2012

Science in Seconds - Flameproof Balloon?



Cool Science in Seconds - Activity 2: Flameproof Balloon? 

Materials / Apparatus:
- A balloon
- Tap water
- Matches
- 1 candle

Steps:
(1) Fill the balloon with water until it is about the size of a grapefruit. You can do this by fitting the mouth of the balloon over a tap faucet and filling it with tap water.

(2) Tie the mouth of the balloon in a secure knot and shake it so that any excess drops of water fall off.

(3) Lit the candle.

(4) Hold the balloon by holding the knotted end and move it into the flame for a few seconds.

Observations:
The balloon seems to be flameproof!

Teacher Serena's Explanations:
This experiment tells us about heat absorption. 

If we hold a balloon filled with air in the flame, it will burst. Why is this so? The heat of the flame will weaken the rubber until it can no longer withstand the pressure of the air inside.

Why does the balloon in our experiment not burst? Water absorbs heat very well. The water inside the balloon absorbs the heat of the flame. Hence the balloon does not burst. 

~ Serena's Greenhouse







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