Fire proof balloon !

Yesterday was science day. 

We know that balloons are very fragile . If a balloon is filled with air. then it has to be kept away from sharp objects and also from fire . Because a fire can weaken the rubber. of which balloon is made of , and cause it to burst. Now in this experiment , our inflated balloon acts as fire proof ! This fire proof balloon experiment is very simple. All we need is two non inflated balloons , fire and water. First take one balloon and fill it with air . Tie the mouth tightly. Now hold this balloon over fire. Balloon breaks. WHY ????? ???? It is because of heat expansion . Now what is getting expanded ? Air inside the balloon. Now take the other balloon. Fill it with little water and then fill it with air. Tie the mouth tightly . Now hold this balloon over fire. It will not break , how long the time is !!! WHY ??????? ?????? ?????? Let me explain . This balloon is filled with air and water . As water is heavier than air. It settles at the bottom of balloon . So when we are heating it , water first starts to get heated . Remember. water is a good absorber of heat. So, water absorbs all the heat  Thus  air will not get heat to expand . That's why the balloon acts fire proof.