Get ready to amaze your little ones with a rising water candle experiment! This experiment not only looks super cool, but it’s also a wonderful way to introduce some basic scientific concepts like what a fire needs to burn, air pressure, and equilibrium. Best of all, you only need a few household items, so it’s perfect for a spontaneous afternoon science activity!

Celebrations Family Unit Study Bundle

This rising water experiment is one of the hands-on activities from Birthday School.

If you’ve never heard of Birthday School before, you’re in for a treat! Birthday School is the perfect unit study to dive into during your child’s birthday month. You’ll learn about fun birthday games, some delicious (and maybe not-so-delicious!) birthday foods, make a colorful present, and so much more. It’s a wonderful way to harness all of that birthday energy and inject some celebratory fun into your homeschool routine.

There’s also Halloween School, Christmas School, Valentine’s Day School, AND Easter School!

You can grab ALL of these celebration family unit studies in the Celebrations Family Unit Study Bundle (such a clever name, I know). All celebrations are presented with a secular framework, focusing on the magic of the holidays without religion. We know you will love them every bit as much as your child as you build memories to last a lifetime!

Check out a sample and grab your copy right here: https://shop.howweelearn.com/products/celebrations-bundle

How to Perform the Rising Water Candle Experiment

Below, I’m going to share with you exactly how to set up and perform the rising water candle experiment, the science behind what’s happening, and an optional extension activity.

Materials

For this experiment, you will need:

• shallow dish
• tealight or small candle
• glass jar or vase
• water
• lighter or match
• food coloring (optional)

Rising Water Candle Experiment Instructions

1. Pour some water into a shallow dish so it’s about 1/2″ full. You could also mix in a couple of drops of food coloring into the water if you’d like.

2. Float a tealight on top of the water and carefully light it.

3. Next, you’re going to place a glass jar over the tealight. What do you think will happen? Make your predictions!

4. After you place the glass jar over the tealight, you’ll notice the flame goes out. You’ll also see the water slowly move up inside the jar, pushing the tealight up with it! How does this happen? Read on to find out!

What’s Happening in the Candle Experiment?

Let’s chat a bit about what’s happening in this experiment and why!

For a candle to burn, it needs three things:

1. a heat source,
2. fuel, and
3. oxygen.

The heat source is the fire from the lighter or match, the fuel is the candle wax, and the oxygen is in the air all around us.

You can make the flame go out by removing either the heat source, fuel, or oxygen:

• If you blow on the flame, it will go out because you removed the heat.
• If the wax runs out, the flame will go out because there is no more source.
• Or, you can make the flame go out by removing the oxygen!

When you place the glass jar over the candle, the candle quickly uses up all of the available oxygen in the jar, then the flame goes out.

But why does the water get drawn into the jar?

The heat from the candle makes the air in the jar hot. Hot air takes up more space, increasing the pressure inside the glass jar. You may even see a few bubbles escaping from the bottom edge of your jar as some of this excess air tries to escape.

When the flame goes out, the air cools off again, lowering the pressure inside the glass jar. Now, the pressure outside of the jar is higher than the pressure inside the jar. This creates a vacuum, where the water gets drawn into the jar until the pressure inside and outside the jar is the same. This is called equilibrium!

Optional Rising Water Extension Activity

Now that you know how this rising water candle experiment works, you can try changing some of the variables and predicting what might happen!

What happens if you change:

• the size of the jar?
• the size of the candle?
• how much water is in the dish?

Do you think changing any of these variables will affect how much water is drawn into the jar? Try it and find out!

When we tried two tea lights and a vase, it sucked up ALL of the water (and ended up submerging the tea lights). That particular combination got a lot of oohs and aahs from the kids—and from me!

I hope your children enjoyed this experiment and learned something new. Now, let’s keep that hands-on learning going all year long with the Celebrations Bundle! Grab your copy right here:

Celebrations Family Unit Study Bundle

https://shop.howweelearn.com/collections/celebrations-family-unit-study-bundle

Thank you so much for reading, my friend!

xo
Sarah