It’s that time of year again! Kids are back to school and ready for a new year of learning! With this in mind, we wanted to offer teachers, parents, and students a fun, educational experiment using dry ice that can be done in the classroom or at home.

This experiment will show how carbon dioxide (CO2) is heavier than air – with balloons! What kid doesn’t love balloons? So what better way to help them learn about different gases and their weight than to use a fun, hands-on experiment to show them?iStock_000018314922Large

What You Need

  • An empty plastic bottle
  • Insulated gloves
  • Tongs
  • Balloons
  • Dry ice pellets
  • Small amount of water

Before You Get Started

Before you get started with your experiment, make sure you’re either in a well-ventilated room or outside and that an adult is present. Because carbon dioxide (CO2) is heavier than air (which is what you’re trying to prove – safely) it displaces oxygen and, therefore, presents a suffocation hazard. You can also read about the best Safe Handling of Dry Ice practices here to make sure all proper precautions are taken before and during your experiment.

What You Do

First, blow up a balloon with regular air, tie it off, and set it aside.

Second, take the empty plastic bottle and open it. Third, take the tongs and use them to place a couple pellets of dry ice in the plastic bottle. Pour a small amount of water into the bottle over the dry ice. Then, place the opening of a balloon on the opening of the bottle. Watch as the balloon expands as the dry ice sublimates, or turns from a solid to gas form, and inflates the balloon. When the balloon is fully inflated, remove it from the bottle and tie it off.

Warning: Under no circumstances should the bottle be capped.

Now that you have two inflated balloons – one filled with normal air, one filled with carbon dioxide – designate two children to each hold a balloon. Then, instruct them – on the count of three – to toss the balloons and watch as the balloon filled with carbon dioxide falls more quickly to the ground than the balloon filled with air.

This is because carbon dioxide is heavier than air and you’ve just seen it with your own eyes!