Fizzy Rainbow Experiment and Free Printable

Kindergarten students LOVE anything colorful, especially when it’s combined with cool science experiments. With St. Patrick’s Day coming up, we just knew we had to do a fun activity involving rainbows. This fizzy rainbow STEAM experiment is going to amaze your whole class, and you’ll love the FREE printable with the details ready for you. Keep reading for all the info and grab your copy!

This Fizzy Rainbow STEAM Experiment Is perfect for St. Patrick's Day! Your students will learn about color mixing, reactions, and more!

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Fizzy Rainbow Experiment

This beautiful fizzing rainbow is perfect for March! All you need are a few dollar-store materials to get the experiment going. Your students will learn about chemical reactions, color mixing, sensory input, and more as they are completely fascinated by what’s happening! As an added bonus, you can reuse the paper towels that get stained with the colors as an art project, making this the perfect STEAM activity this month.

Getting the Activity Started

Now that you know what the fizzy rainbow looks like, it’s your turn to complete the experiment with your preschool, kindergarten, or first-grade class. We suggest doing this as a whole-group observation where you are the one to complete the steps.

Vocabulary Words:

There might be a few words your students haven’t heard before. Here they are for you to describe:

  • Reaction: A response to a situation
  • Fizzing/Fizzy: Create bubbles of gas to make a hissing sound
  • Primary Color: The basic colors on the color wheel- red, yellow, blue
  • Secondary Color: Colors that are made by mixing two primary colors together- orange, green, purple

Materials for the Fizzy Rainbow:

This experiment looks amazing but only needs a few items to pull it off. We got everything from the dollar store!

  • 7 small clear cups
  • Food Coloring (Red, Yellow, Blue)
  • White vinegar
  • Baking Soda
  • Cookie Sheet
  • Paper Towels

Simply Beautiful with Simple Steps

Something that looks so pretty couldn’t possibly be easy, could it? It sure IS! Here’s all it takes:

  1. First, place a double layer of paper towels on a cookie sheet.
  2. Next, set up 6 of the little cups in a rainbow arc shape on the paper towels. Put the 7th cup in the middle or off to the side for now.
  3. The next step is where you will teach about combining colors! Place food coloring in order of the rainbow to fill the bottom of each cup (about 5 drops.) Red for the first cup, yellow for the third cup, and blue for the fifth cup.
    *Student Question Time* Ask the class, “Which two primary colors can we mix to make orange?” You should do this as you add food coloring, asking for volunteers to tell you what color comes next, and if it’s a primary or secondary color.
  4. Now you will fill each cup up with vinegar until they’re about 3/4 full (or a little more if you want to use less baking soda.)
  5. Fill the last little cup full of baking soda.
    *Student Question Time* Ask the class, “What reaction do you think is going to happen when we pour the baking soda into the vinegar?”
  6. Time for the fun part! Sprinkle baking soda into each colored cup and stand back so your students can watch!
    *Student Question Time* The last question you can ask is “Do you notice that the rainbow cups are fizzing? What does that sound like? What does it look like?”

Bonus Fizzy Rainbow Projects

If you lay the paper towels flat and dry them, they end up with beautiful colors and designs! Give each student a small square and practice drawing shamrocks, writing a note, or coloring their own rainbow! There is also a bonus writing extension included in the free printable for students to draw and complete a writing prompt!

Other Science Experiments

Did you know that Simply Kinder has an ENTIRE bundle of Kindergarten science experiments? Your students will love completing these all year long! Low-prep, themed, educational, and hands-on makes it the perfect resource for you! Your students are going to LOVE the candy peeps expirements to do next month! Get the entire bundle from Simply Kinder when you click here or from TpT by clicking here!

Free Printable


Ready to get this amazing fizzy rainbow started? Use these pages to have students reflect on the experiment, show the food color combinations, and write a response. Grab it inside Simply Kinder + Printable Membership instantly here!

We would LOVE to see your experiment results. Make sure you tag #simplykinder if you share any photos on Instagram. Or tell us in a post on our Simply Kinder Teacher Group Facebook Page.

This Fizzy Rainbow STEAM Experiment Is perfect for St. Patrick's Day! Your students will learn about color mixing, reactions, and more!

This post was written by Johanna, an experienced early elementary teacher who loves learning about new teaching ideas for preschool, kindergarten, and first grade!

At Simply Kinder we work together to bring you ready-to-use resources to partner with great teaching for any curriculum, a Facebook community where teachers talk all things Kindergarten, and low-prep learning ideas that your students will love. Be sure to stay up to date with all things kindergarten on InstagramFacebookPinterest, and through email. Simply Kinder: where teaching Kinder is definitely better together!

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