Looking for a colorful and easy way to introduce kids to the wonders of science? Our Rainbow Paper Towel Experiment is a fantastic way to explore capillary action. Grow a rainbow before their eyes with a STEAM activity perfect for preschoolers and early elementary students.
Grow A Rainbow Experiment
This experiment not only demonstrates capillary action but also encourages kids to make predictions, observe changes, and ask questions about what they see. Plus, the bonus of seeing a rainbow appear right before their eyes is sure to captivate their imaginations!
Recommended Age Range: 3-8 years old (Preschool through early elementary grades)
Supplies Needed:
- 1 paper towel (either 1 select-a-size or a full paper towel cut in half)
- Scissors
- 2 clear 6 oz cups
- 1 cup of water
- Washable markers (red, orange, yellow, green, and blue)
💡 For older kiddos, try this marker chromatography experiment!
Watch the Quick Video:
How To Set Up Your Experiment
STEP 1: Gather all the supplies you’ll need for the experiment. Fold the paper towel in half and cut off ⅓ of one end.
STEP 2: Use the washable markers to color a rainbow on both ends of the paper towel. Make the stripes about 1-2 inches long.
STEP 3: Fill both clear cups ¾ full with water.
STEP 4: Place half of the paper towel rainbow into each cup of water.
Now, watch the rainbow grow before your eyes!
How Does It Work?
So, what’s happening here? This experiment shows how water travels through the paper towel, carrying the colors with it.
This process is called capillary action, which is how water moves through plants, bringing nutrients up from the roots to the leaves. Capillary action is the ability of water to move through tiny spaces, even against gravity.
💡 Here are more simple ways to explore capillary action with kids.
Extend The Learning
Color Mixing Experiment
After completing the grow a rainbow experiment, try using primary colors (red, blue, yellow) and see what happens when the colors mix as they “walk” into each other. Discuss with your child how primary colors combine to make secondary colors.
💡 Here are more ways to explore color mixing with preschoolers.
Celery Experiment
Extend the concept of capillary action by placing a white carnation or celery stalk in colored water. Observe how the color travels up the plant, similar to how it moved through the paper towel.
Compare Different Materials
Experiment with different types of paper (coffee filters, tissue paper, etc.) to see how capillary action varies with different materials. Which material makes the colors travel faster or slower?
Make a Walking Rainbow Chain
Use multiple cups and paper towels to create a longer chain of rainbow colors walking from cup to cup. How far can the colors travel? This activity can lead to discussions on how distance affects the process.
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
