You won’t believe your eyes when a flame appears to be burning underwater in this super cool Candle Water Experiment! Let’s jump in and find out how to make a candle burn underwater!
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This cool science experiment for kids is a great way to demonstrate the high heat capacity of water! Your kids will be both entertained and educated with this experiment, but they will need some adult supervision.
Candle Water Experiment
Underwater Candle Experiment
- Cut a tall candle down to just below the height of your bowl.
- Stand the candle up in the center of the bowl and secure it with modeling clay.
- Fill the bowl with water to a height that is just below the top of the candle.
- Light the candle with a lighter or matches.
- Watch for a few minutes as the candle burns down below the water level!
Step 1: Cut a Tall Candle To Stand Below the Rim of Your Bowl
Remember that since this experiment does require sharp scissors and sizzling fire, adult supervision is required!
Now get ahold of a pair of scissors and carefully cut your tall candle down to a length that is just barely lower than the height of the bowl you will be using.
You might want to measure the height of your bowl from the inside bottom to the rim of the bowl to help get the candle to the right height. You can also just eyeball it and it should work just fine!
Step 2: Stick The Candle to The Center of The Bowl
After you have cut your candle down to the right size, get some modeling clay and work it into a nice round flat circle.
Place the modeling clay on the inside bottom center of the bowl and then attach your candle to it with the candle standing up. Don’t be afraid to apply some pressure pushing the candle down to make sure it holds in place!
This should secure your candle to the bowl with the candle standing up in the middle and center of the bowl.
Step 3: Add Water To The Bowl
Gently and carefully pour enough water into the bowl so that the water level is almost to the same height as the candle, but just a touch below the wick of the candle.
You just want to be careful not to pour the water too quickly or it could knock the candle over.
Step 4: Ingite the Candle
Okay now we are getting to the fun and exciting part! Again…with adult supervision grab some matches or a lighter and get that candle burning!
Step 5: Wait For The Candle To Burn Below The Water Level
Once the candle is burning, watch and wait for several minutes as the wax begins to melt and the candle starts to get shorter and shorter.
Eventually, the wick and the inside core of the candle will drop below the water level and keep burning while the outer edge of the candle wax stays higher with the water level.
This will give the appearance that the candle is burning underwater, but is that really the case!? Let’s dive into the fun science behind how this underwater candle experiment works to find out!
Candle and Water Experiment Explanation
The magical science behind this candle and water experiment is really thanks to the high heat capacity of the water in the bowl surrounding the candle.
As the wick of the candle burns, the hot flame melts the wax immediately around the wick, but the water keeps the layer of wax on the outside of the candle cold enough to not melt.
The water is able to keep the outside of the candle cold enough thanks to water’s incredible ability to absorb heat and energy, which is referred to as the heat capacity of water.
For another cool way to demonstrate the heat capacity of water, check out this How to Fireproof a Balloon experiment!
This is the same reason that the sun will heat up the air around us to a hot temperature much quicker than a swimming pool full of water will heat up!
So even though the wick and the flame have dropped below the water level, it will continue to burn because the outer part of the candle wax is still solid and acts as a barrier to keep the water from getting to the flame.
Eventually the wax on the outer diameter of the candle will soften enough to allow water to leak in and fill the area around the wick and extinguish the flame.
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