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You’ve got to try this fun and simple rainbow sugar density experiment! Anytime there is a rainbow of colors involved in a science experiment or craft, we immediately love it. This experiment allows layers of colors to form using just sugar and water and coloring. See more Rainbow Science Experiments.
This science project idea came from our Steve Spangler Science kit that we get monthly. I got this subscription for my son for school this year and it has been such a great investment. I highly recommend them! (See also my post about the Gravity Beads experiment from Steve Spangler, another huge hit!)
How to Do the Rainbow Sugar Density Experiment
If you don’t have sugar cubes, no problem! One sugar cube is equal to 1 tsp or about 4 grams.
Number your cups from 1-6. Add 3 ounces of hot water (or about 1/3 of a cup) to each cup. Add food coloring to each cup to make a rainbow. Start with red in cup #1, orange in #2, yellow in cup #3, green in cup #4, blue in cup #5, and purple in cup #6. The Steve Spangler kits come with fizzing colored tablets that are fun to work with and easy to color the water with.
Each cup is going to get a different amount of sugar cubes. This is what makes the layers because the more sugar there is in the water, the more dense it will be.
- In cup #1 there will be no sugar.
- Put 3 sugar cubes into cup #2.
- Put 5 sugar cubes into cup #3.
- Put 7 sugar cubes into cup #4.
- Put 9 sugar cubes into cup #5.
- Put 11 sugar cubes into cup #6.
Stir the cups until the color and the sugar are both dissolved into the water.
Now it’s time to add the layers into the syringe. Start with cup #1 and add 2 mL of the red water. Next add 2 mL of the orange from cup #2.
Continue in order through each of the six cups. Add each layer slowly so the layers do not mix. The layers will stay separated and make a rainbow of colors!
Try slowly flipping the syringe and the colors will reverse!
Try another fun Density Experiment for Kids!