Make a Floating Rainbow in 4 Easy Steps

Fun and Easy Science Experiment for Kids

In honor of St. Patrick’s Day, I thought I’d write about one of my children’s favorite science experiments. My kids love hands-on activities and one of our favorite things to do in the afternoon after school is science experiments. This particular science experiment is called the Floating Rainbows Experiment and is designed to teach your young scientists several science concepts: color names, sinking/floating, and mixing/separating.

Here's a FUN and EASY science experiment you can do at home with your kids. Learn how to make a FLOATING RAINBOW in 4 Simple Steps.

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For this fun and easy experiment, you probably won’t need to purchase anything at all! You should be able to find most if not all of these items in your kitchen or pantry. Here’s the list:

Once you’ve gathered your supplies, you are ready to start experimenting! To cut down on the mess, I usually use plastic trays for each child. (HINT: These trays also work great for serving food to your children. We call them “Breakfast Trays” and each child has his own special color.)

STEP ONE: Fill The Glass Jar With Water And Oil

For the first step, take the glass jar and fill it with water, leaving just a little bit of room for the oil.  I fill plastic pitchers with water and then the children pour the water into the jar. You’ll then add about a 1/4 cup of oil so there’s a nice, thick oily layer on top.

STEP TWO: It’s Food Coloring Time!

Next, you can have your child start adding the food coloring. We added a few too many drops. You really only need about 1-2 drops of each color. We used about 3-4. The drops will immediately form bubbles and they will stay “separate” from the oil. You can observe the bubbles “floating” around for a few minutes.

STEP THREE: Wait For The Magic To Happen

Now you wait for the magic to happen. It took about 2-3 minutes, which seems like an eternity for a little one, but then the drops of food coloring begin to drop from the oil into the water. When this happens you and your children can discuss science concepts like how the bubbles “sink” into the water, and how the food coloring “mixes” with the water. When the food coloring begins to mix in with the water you will begin to see a beautiful rainbow of colors forming in the water.  The kids love to watch this happen!

STEP FOUR: Observe The Rainbow

After about 5-10 minutes all of the food coloring bubbles will have mixed in with the water and you are left with a “floating rainbow” in the jar. There will still be a thick layer of oil still on top. You can discuss how oil and water don’t mix together the way that food coloring and water do mix together.

That’s it for this quick and easy science experiment that’s fun and fascinating for your littler scientists!

If your kids want to keep on experimenting, you can vary the temperature of the water up or down for a slightly different outcome.

Have fun experimenting with your kids!

With Love and Joy,


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