🌈 Grow a Rainbow - Capillary Action Experiment for Kids

Amaze your kids with this SIMPLE grow a rainbow activity! This spring science experiment allows preschool, pre-k, kindergarten, first grade, 2nd grade, and 3rd graders to learn about capillary action with a beautiful walking water science experiment. This kindergarten science experiment explores capillary action for kids with a few simple materials and only takes 5 minutes!

Grow a Rainbow

I love science activities for kindergarten that WOW without a lot of fuss. Young students tend to get easily distracted so doing a grow a rainbow experiment that only takes about 5 minutes is perfect for this age group! Try this rainbow experiment with toddlers, preschoolers, kindergartners, grade 1, grade 2, and grade 3 students to learn with a capillary action experiment. This spring science experiment is perfect for rainbow or weather themes at home or in the classroom.

Grow a Rainbow Experiment

All you need to try this easy science experient for kindergartners are a few simple materials you already have on hand:

2 glasses
water
washable markers
paper towel

Capillary Action Experiment

Now you are going to make a block of each color, in rainbow order as shown above, on each side of the paper towel. You want it to be a solid block in the same order as the other side, so color it in well. But the middle section is all white.

HINT: The markers must be washable markers. In other words they are water based and will move when they come into contact with water for our experiment. Permenent markers will NOT work for this experiment.

Rainbow Experiment

Now you will need two glasses filled at least 1/2 full with water. You want to space them so that your paper towel reaches both sides. The colors should just barely touch the water. If you put too much of the colors in the water the colors will move to the water instead of flowing towards the other side of the rainbow.

Walking Water Science Experiment

Almost immediately you will notice the colrs are starting to move towards each other.

Spring Science Activities for Preschoolers

Continue to watch as the walking water experiment continues to unfold very quickly in front of your eyes. As the water travels up the paper towel, it will take the colors with it.

Spring Science Experiment

Right before your eyes you will have grown a rainbow! Not only is this a pretty science experiment perfect for spring or summer, but it teaches a scientific principal too!

Capillary Action for Kids

This simple, beautiful experiment teaches the principal of capillary action. Capillary action is the name of the process that moves liquids up through a solid (paper towel). This moving of water is how plants drink. In our experient the moving water took the washable dye molecules with it because they are water based and dispersed in the water. Water molecules are considered cohesive (sticky to each other) and they adhere (stick) to the paper towel. As one water molecule moves up the paper towel it pulls the other molecules with it. The molecules pull each other along like a drawstring.

Kindergarten science experiment

This pretty science experiment takes less than 5 minutes and is super quick to clean-up. Simply throughout the paper towel (or dry it outside for a pretty decoration). Dump the water down the drain or outside on the lawn and wash out the canning jars.

Science activities for kindergarten

We had our paper towels too far in the water this time we did this experiment. Although it still worked, while the water molecules were traveling up with the dye, the dye under the wtaer was also dispersing and coloring the water. Ideally just put the tip of the paper towel touching the water for the best, quickest, and most reliable results with this colorful science experiments.

Grow a rainbow in less than 5 minutes! This SIMPLE spring science experiment teaches about capillary action with pretty walking water science experiment.