This colorful experiment shows how density works using Skittles candy. You’ll make a rainbow of sugar water layers – all from the same candy!
Materials:
• Skittles (red, orange, yellow, green, purple)
• Six clear glasses
• 1/3 measuring cup
• Spoon for stirring
• Pipet or dropper
• Boiling water
Safety:
Always have an adult help you when using hot or boiling water. The water and glasses can get very hot and may cause burns. Never taste or drink the mixtures — they’re for science only!
Experiment:
Line up five separate glasses and add a red Skittle to the first glass. To the second glass, add two orange Skittles, then three yellow Skittles to a third glass, four green Skittles to a fourth, and finally five purple Skittles to a fifth glass. Add 1/3 cup of boiling water on top of each of the Skittles in each glass and stir until the Skittles are completely dissolved. If they haven’t completely dissolved, put them in a microwave for a short time to reheat the water.
One the Skittles solutions have cooled, pour the purple solution into the sixth glass. Then use a pipet to pull up the green solution and, very carefully, as you touch the side of the glass with the pipet, add the green solution by letting it run down the side of the glass on top of the purple. Once all of the green solution has been transferred, continue on in order: yellow, orange, and finally red.
What’s happening?
Each layer has a different density because the more Skittles you dissolve, the more sugar is in the water — and the heavier (denser) it becomes. Even though each glass has the same volume of liquid, the bottom layers are heavier and sink below the lighter ones, creating a rainbow effect!
Extension:
Could you add a water layer to the top? What do you think would happen if you put the red solution in first and did things in the reverse order? Would your rainbow still stack up?
References:
https://www.mybaba.com/skittles-density-tower/
To view past “ChemShorts for Kids” activities, go to:
https://chicagoacs.org/ChemShorts.
