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Radiant Rainbows (Awesome Summer Science Experiments)

Check in each week at Science Buddies this summer for our Awesome Summer Science Experiments series! Each week, we'll highlight a few activities for awesome science and engineering kids can do at home. We've got a whole summer of fun STEM themes lined up for kids of all ages — for free. This week: awesome summer science experiments with colorful rainbow flair.

 Radiant Rainbows Week 7 of Awesome Summer Science with Science Buddies

Awesome Radiant Rainbow Science

The activities in Week 7 of our Awesome Summer Science Experiments series feature colorful explorations with vivid, rainbow flair.

Awesome Summer Science Experiments Week 7: Experiment | Watch | Ask | Explore | Read

EXPERIMENT: Radiant Rainbow Science

Milk Rainbow Surface Tension

With milk, food coloring, and liquid detergent, kids can learn about surfactants and hydrophilic substances as they create colorful patterns on the surface of milk. What colors will they choose for their milk rainbows? What about dish soap causes the spread of the color when a cotton swab with liquid soap is touched to the surface of the milk? Can they master the science behind the experiment to create their own mesmerizing color displays?

Make a Rainbow and Identify the Colors

How many colors are there in a rainbow and how is a rainbow created? With this hands-on make a rainbow activity, kids can create rainbows and learn why we see the colors we see. Using a glass container of water, the sun, and sheets of white and colored papers, kids learn about white light and how refraction and reflection create the colors we see in a rainbow (or when using a prism). How many colors will you see in the rainbows you create?

Rainbow Density Column

Finding the right way to stack liquids (and understand why they stack) is a fun way to learn about the density of liquids. With a bit of creative thinking, kids can use food coloring to turn their homemade density column into a brilliant rainbow stack! Figuring out the order of the liquids to pair with the desired order of colors is part of the challenge! Stacking liquids is a bit like building a tower. Can you go all the way to the top of the container without anything breaking through? What can you add to a liquid to alter its density?

Underwater Color Explosions

Use cooking oil, water, and food coloring to create beautiful underwater color bursts and explosions. In this experiment, kids learn about the miscibility of substances and the concept of diffusion. Try both parts of the experiment to see how the results vary when you start with a cup of water compared to when you start with a cup of oil. Which one creates the most colorful patterns? Which one creates blobs of color?

3D Print a Rainbow with Sand and Glue

In this fun science experiment, kids can explore the additive process used in 3D printing by making small 3D printed sculptures with sand and glue. No 3D printer is needed for this experiment. Kids can use favorite colors of sand for their creations, or try making a rainbow stack like the example shown. Can they solve the layering challenge to "3D print a rainbow"?

Candy Rainbow

With colorful candies and water, kids can experiment to use the power of diffusion to create colorful candy rainbow displays. When the candy coatings begin to dissolve, what happens to the color? How can additional sugar be used to create even more interesting patterns? The variations and possibilities are endless! Can your kids figure out how to make a heart shape from this experiment? Be inspired! There might be some spoilers here, but this family did a great job making colorful creations with this experiment.

Walking Water Rainbow

Thanks to the power of capillary action, strategic placement of paper towels in cups of colored water separated by empty cups will, over time, result in a pretty cool walking water rainbow! Kids can use fewer cups for a shorter experiment or change the configuration. What happens if all of the cups of colored water lead to just a single central empty cup? If they change the arrangement of the cups, what colors will they create?

WATCH: Videos

Liquid Density Column – STEM Activity
Underwater Color Bursts – STEM Activity
3D Printing with Sand and Glue (no 3D printer required!)
Walking Water Experiment | STEM Activity
Candy Diffusion Art

ASK: Questions

Use these questions to prompt conversation and reflection about the science behind this week's Awesome Summer Science Experiments activities:

  • How is a rainbow created in the sky?
  • What happens to light to make a rainbow?
  • In the experiments this week, what kinds of science concepts explain the colorful patterns you created?


After trying this week's summer science experiments, kids can learn more about related science and engineering careers, like:

READ: Books

Pair picture and story books like these with this week's Awesome Summer Science Experiments explorations.

Spike: The Penguin With Rainbow Hair  cover How the Crayons Saved the Rainbow  cover Rain Before Rainbows cover The Little Raindrop  cover The Day the Crayons Quit  cover Esther's Rainbow  cover Raindrops to Rainbow cover There is a Rainbow  cover

Bookmark Awesome Summer Science Experiments Week 7:

Walking water, underwater color bursts, milk magic rainbow, 3D printing with glue and sand in rainbow colors, and rainbow candy diffusion patterns - Week 7 Radiant Rainbow Science - part of Awesome Summer Science Experiments series

For more suggestions for science-themed summer reading, see our Summer Reading List. Also, don't miss this roundup of creative STEM activities for storytelling and imaginative play.

10 Weeks of Awesome Summer Science Experiments

Follow the full summer series on the Awesome Summer Science Experiments page!

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