candles science experiment air pressureLooking for a fun science experiment you can do with your kids and just a few kitchen items? It relates to air pressure. The main lesson kids will learn is that air wants to travel from high pressure to low pressure.


  • A plate
  • A lump of clay
  • A birthday candle
  • Water
  • Food coloring
  • Matches (parents, you’re in charge of these)
  • A tall glass


  1. Stick a candle into a lump of clay and place it in the middle of the plate.
  2. Pour water into the plate so that it fills it. Add a drop or two of food coloring.
  3. You’ll put the glass over the top of the lit candle in a moment. But first have your child make a hypothesis/guess about what he thinks will happen.
  4. Light the candle.
  5. Hold the glass over the candle.
The scientific lesson is this: 
The outside air (high pressure) wants to push into the glass (low pressure). 


You’ll see the candle flame slowly extinguish and then the water will creep up into the glass. Pretty amazing!


Have your child experiment with more or less water, or more candles. It’s a way to make learning fun. 

How does it do that?

The hot air created by the burning candle pushes air out from under the glass (hot air expands and causes bubbles at the bottom). As soon as the candle goes out, the air cools and condenses, but now there’s less air in the glass than before. This is low pressure. 

Steve Davala is a middle school science teacher who likes to write. He has two kids of his own and subjects them to science activities as guinea pigs. Follow him on Twitter or visit his website.

What are some fun, creative science experiments you've conducted with your kids?