Science Kids at Home
Science Gifts for ChildrenScience Experiments for Children

Hot Air Balloon Inflating

Use hot and cold air to inflate a balloon.

Continue reading "Hot Air Balloon Inflating"





Hot Air Balloon Inflating

Materials - balloons, plastic pop bottles, hot and cold water

The results of this experiment are more interesting if it can be done twice, first with a small bottle, and second with a large bottle. A third bottle (small) can be used as the control. The final step should be done in a sink or outside as water may overflow.


  1. Stretch out the balloons as if you were about to blow them up.
  2. Stretch the neck of a balloon over the top of two bottles the same size.
  3. Pull the balloon down so that the neck of the balloon goes over all the threads of the bottle.
  4. Place one bottle with the balloon into the freezer for 5 minutes, or 30 minutes for a dramatic effect.
  5. Put the second bottle on the counter as a control.
  6. If you have a large bottle and and extra balloon, put the balloon over the bottle and place it in the freezer too.
  7. hot air pressure and balloon Run hot water to partially fill a sink, pitcher or pot.
  8. Take the small bottle from the freezer and put it in the container of hot water until the water is ¾ up the side of the bottle. Hold it in place. Watch what happens.
  9. Take the large bottle from the freezer and put it in the container of hot water until the water is ¾ up the side of the bottle. Hold it in place. Watch what happens.
  10. Take the bottles out and empty the hot water.  Use room temperature water to fill the sink, pitcher or pot.
  11. Put the control bottle in the container until the water is ¾ up the side of the bottle and hold it place. Watch what happens.


cold air pressure and a balloon What should happen?

When the balloon was placed in the freezer for a short time, it would collapse. After 30 minutes, the cooling air sucks the balloon into the bottle.

When the bottle was placed in the hot water, the balloon should expanded slightly. When two different-sized bottles are used, the smaller one would have only expanded the balloon slightly; the larger bottle would have expanded it more.

The balloon on the control bottle should have remained unchanged.

Notes to Parents:

  1. Every parent must use their own judgment in choosing which activities are safe for their own children.  While Science Kids at Home makes every effort to provide activity ideas that are safe and fun for children it is your responsibility to choose the activities that are safe in your own home.
  2. Science Kids at Home has checked the external web links on this page that we created.  We believe these links provide interesting information that is appropriate for kids.  However, the internet is a constantly changing place and these links may not work or the external web site may have changed.  We also have no control over the "Ads by Google" links, but these should be related to kids science and crafts.  You are responsible for supervising your own children.  If you ever find a link that you feel is inappropriate, please let us know.

send email to Science Kids at HomeSend us a note if you have any questions.


Kids Science Gifts  Science Experiments  Science Fair Projects  Science Topics  Creative Kids Blog

Kids Crafts  Privacy Policy  Copyright © 2016 Science Kids at Home, all rights reserved.