The Candle and Rising Water Experiment

A Peculiar Playdate #7 ∙ Published Mar 5, 2019
Keedoo Raising Water Experiment - Glass over a candle
How do you do a rising water experiment with a candle? Well, from a previous experiment we have learned that the hot water can indeed flow up because of the density difference with a cold one. In this article, we are utilizing air pressure. For that, we’ll need a candle to heat the air. So, without any further ado, let’s get into it.
What you need
  • Candle
  • Matches or lighter
  • Plate
  • Glass
  • Some water (we used a few drops of food coloring to make it look more fun!)
Keedoo Raising Water Experiment - Things you need
How to make it
Keedoo Raising Water Experiment - Place candle on plate and light it up
Step 1
Place a candle on the plate and light it up
Keedoo Raising Water Experiment - Pour water onto the plate
Step 2
Pour a bit of water onto the plate
Keedoo Raising Water Experiment - Place glass over a candle
Step 3

Lower a glass over the candle

What happens
Whaaat? The water is being sucked into the glass and rising up!
Keedoo Raising Water Experiment - Glass over a candle 1
Keedoo Raising Water Experiment - Glass over a candle 2
Keedoo Raising Water Experiment - Glass over a candle 3
Why it happens

The rising water experiment works because of the difference in atmospheric pressure. Let’s dive deeper into this. When you place a glass over a candle, the flame heats the air inside. When hot air expands, it takes more space. You probably know that, if you keep a glass over the candle, then at some point the flame will fade out due to the lack of oxygen. At that moment, the air inside the glass will cool down and free up some space. This event creates a pressure that is lower (a vacuum) than the one outside the glass. As a result of the things that happened inside the glass, the outside air pushes the water into the glass. It will stop eventually when the air pressure is equal both inside and outside of the glass.

Feathers in exchange for prizes

While working on this playdate idea, our Keedoo Parrot has lost three feathers 😔 Please help us! Collect them by bringing this idea to life with your kids, and we will gratefully exchange them for valuable prizes.
  1. Try making this experiment
  2. Share your experience on Instagram or Facebook
  3. Mention @getkeedoo in comments
  4. Nominate two families to do the same
  5. We will contact you to add three feathers to your Keedoo account that you can exchange for prizes in our mobile app
  6. Follow @getkeedoo on Instagram to see new prizes
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