Kids, Try this at home!

Warning: Do this activity with an adult!  Be careful when using matches that you don’t burn yourself or accidentally start a fire.

Materials:

water, two balloons (not inflated), matches               

Instructions:

1. Inflate one of the balloons and tie it with a knot.
   
   
2. Put 60 milliliters (1/4 cup) of water in the other balloon.  Inflate it and tie it with a knot. 
   
   
3. Light a match and put it under the first balloon.  Let the flame touch the balloon.  Think about what’s happening: The balloon bursts!
   
   
4. Light another match but this time put it directly beneath the second balloon with the water.  Let the flame touch the balloon.  What happens to this balloon?  It doesn’t break!  You may see a deposit of soot* develop on the outside of the balloon above the flame. 

What happened? 

Why didn’t the balloon with the water burst?  Water absorbs heat well and so needs a lot of heat to change its temperature.  When the water inside the balloon is above the flame, the water absorbs most of the heat from the flame.  The rubber in this balloon doesn’t get as hot, weaken, or break like the other balloon. 

Warning:  Do this activity with an adult!  Be careful when using matches that you don’t burn yourself or accidentally start a fire. 

*soot:  A dark deposit of unburned fuel residues that’s produced from incomplete combustion of carbon-rich organic fuels without enough oxygen.   (Wikipedia)