Light a fire under middle school science and heat it up! Place a burning candle in the water and watch what happens to the water. Explore how heat affects air pressure for an awesome middle school science experiment. This candle and rising water experiment is a great way to get the kiddos thinking about what is happening. We love simple science experiments; this one is super fun and easy!
Candle in Water
This candle experiment is a great way to excite your kiddos about science! Who doesn’t love watching a candle? Remember, adult supervision is required, though! We love simple science experiments; this one is super fun and easy!
This science experiment asks a few questions:
- How is the candle flame affected by placing a jar over the candle?
- What happens to the air pressure inside the jar when the candle goes out?
💡 Make sure to check out all our chemistry experiments and physics experiments!
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Candle in a Jar Experiment
You need to change one variable if you want to extend this science experiment or use the scientific method for a science fair project.
EXTEND THE LEARNING: You could repeat the experiment with candles or jars of different sizes and observe the changes.
💡Learn more about the scientific method for kids here.
Supplies:
- Tea light candle
- Glass
- Bowl of water
- Food coloring (optional)
- Matches
Instructions:
STEP 1: Put about a half inch of water into a bowl or tray. Add food coloring to your water if you like.
STEP 2: Set a tea candle in the water and light it.
ADULT IS SUPERVISION REQUIRED!
STEP 3: Cover the candle with a glass, setting it in the bowl of water.
Now watch what happens! Do you notice what happens to the level of water under the jar?
Why Does the Water Rise?
Did you notice what happened to the candle and the water level? What’s happening?
The burning candle raises the air temperature under the jar, and it expands. The candle flame uses up all of the oxygen in the glass, and the candle goes out.
The air cools because the candle has gone out. This creates a vacuum that sucks up the water from the outside of the glass.
It then raises the candle up on the water that enters the inside of the glass.
What happens when you remove the jar or glass? Did you hear a pop or popping sound? You most likely listened to this because the air pressure created a vacuum seal, and by lifting the jar, you broke the seal, resulting in the pop!
Related Science Experiments to Explore
- Balloon Rocket: Release a balloon and watch it “rocket” along a string to demonstrate how air pressure changes create movement.
- Balloon In A Jar Experiment: Explore how changes in air pressure can cause a balloon to get pulled into a jar!
- Hot and Cold Air Balloon Experiment: Use a balloon and a plastic bottle to explore how warm air expands (increasing pressure), while cool air contracts (decreasing pressure).
- Tea Bag Rocket (Thermal Expansion): This experiment uses a hollow tea bag to demonstrate thermal expansion. When lit on fire, it rises due to the expansion of air inside.
- Egg in a Bottle Experiment: In this experiment, a hard-boiled egg is sucked into a bottle using the power of air pressure.
- Can Crusher Experiment: Observe how rapid cooling reduces air pressure inside a heated can, causing it to collapse under external air pressure.
Printable Science Projects For Kids
If you’re looking to grab all of our printable science projects in one convenient place plus exclusive worksheets and bonuses like a STEAM Project pack, our Science Project Pack is what you need! Over 300+ Pages!
- 90+ classic science activities with journal pages, supply lists, set up and process, and science information. NEW! Activity-specific observation pages!
- Best science practices posters and our original science method process folders for extra alternatives!
- Be a Collector activities pack introduces kids to the world of making collections through the eyes of a scientist. What will they collect first?
- Know the Words Science vocabulary pack includes flashcards, crosswords, and word searches that illuminate keywords in the experiments!
- My science journal writing prompts explore what it means to be a scientist!!
- Bonus STEAM Project Pack: Art meets science with doable projects!
- Bonus Quick Grab Packs for Biology, Earth Science, Chemistry, and Physics
