HomepageHomepage Showcase


Weather experiment learning about warm air rising

Posted at 6:11 AM, Apr 10, 2020
and last updated 2020-04-10 12:19:07-04

GRAND RAPIDS — It's safe to say we all know warm air rises, but do we know how or why? Today you will be able to see warm air rising right before your eyes! Here is what you will need to get started!

-clear plastic bottle
-two large bowls
-hot and cold water

Step 1: Fill up one bowl with ice water and the second bowl with warm to hot tap water

Step 2: Blow up the balloon to make it more flexible. Deflate the balloon and place it around the opening of your bottle

Step 3: Standing up right place the bottle with the balloon attached inside the bowl of warm to hot water. Wait a few minutes and watch what happens

Step 4: Immediately place the bottle standing upright into the cold ice water and watch what happens.

You just witnessed warm air rising! It’s all due to the temperature change you placed on the molecules of air that reside in the bottle.

When the air inside the bottle is warmed, the air molecules expand and quickly spread out because they need more space, therefore it stretches out the balloon. They are becoming less dense and lighter. When the bottle is transferred to the icy cold water, the air molecules are cooled; they contract and need less space, so the balloon deflates. You can notice that air sinks and becomes more dense as the air molecules slow down and come closer together. The mass of air remains constant inside the bottle, so this shows that the warm air requires more space and is less dense than cool air.

There you have it! Warm air rises! Send our meteorologist Candace Monacelli your pictures doing this experiments at home! She will feature future meteorologists on my Facebook page daily!