Kids will love making their very own walking water rainbow from just three colors. It’s amazing how color mixing can make something spectacular!
Walking water is a classic science experiment that we’ve tried before. But this year, Monkey realized that she could make the entire rainbow this way starting with just the primary colors. It was a lot of fun to watch the rainbow form right before our eyes!
This lesson teaches color theory, capillary action, the scientific method, and engineering.
Don’t miss the complete list of spectacular STEM activities you can do at home!
Kids will have a blast with this simple rainbow science experiment!
RAINBOW WALKING WATER SCIENCE EXPERIMENT
This simple project packs a lot of learning into a tiny package! Kids will love watching the colors slowly transform over the course of 48 hours.
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WHAT KIDS LEARN WITH THE RAINBOW WALKING WATER SCIENCE EXPERIMENT
The rainbow walking water science experiment teaches a few basic scientific concepts. When the paper towels are rolled up and placed between two jars, they exemplify capillary action, which is how liquid can move up something, rather than follow the usual pull of gravity and pull down. To get a bit technical, intermolecular forces between the liquid and the paper towel creates surface tension that ract with the adhesive force between the liquid and paper towel. This causes the water to move up the paper towel and into the next jar. Capillary action is how plants pull water from the soil and up into their leaves to keep watered.
Then, once the paper towels pull color from the base red, blue, and yellow primary color jars, the resulting mixture creates the secondary colors of green, purple, and orange, completing the rainbow.
What you need to make the rainbow walking water science experiment:
HOW TO DO THE RAINBOW WALKING WATER SCIENCE EXPERIMENT
Go over the color wheel before starting. Show the kids how mixing colors will create different colors. However, don’t tell them how to make the rainbow!
Let the kids discuss how they will make a rainbow from just three colors. It will take them a little bit to determine the right combination.
If the kids are stumped, you can help them out by reminding them what colors are together in a rainbow.
Put an empty jar between red and yellow, yellow and blue, and blue and red.
Roll the paper towels into tube-like pieces and put one end in a full jar and the other end in an empty jar.
The paper towels will start soaking up the water right away, but it will take about 48 hours before the process is finished. Set a timer to find out exactly how long it takes to start mixing colors.
Within a few hours, you will see the color starting to mix in the empty jars.
Kids will love watching the new colors appear!
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Rainbow Walking Water STEM Integration
Science: Color theory, capillary action. With paper towels (and plants work the same way), the molecules in the water are attracted to the molecules in the paper towels. This causes the water to slowly move from the jar, up through the paper towel, and into the next jar. Eventually, the water level in all the jars will even out. This is one of the most fascinating areas of science!
Technology: Food coloring is a marvel of modern science. We also used a timer to determine how long it took for the water to travel to one container to another.
Engineering: Kids have to set up the experiment properly or it won’t work. If you mix the wrong colors, you won’t end up with a rainbow, but a muddy-looking mess!
Math: Measuring, time estimation, comparison.