STEM Activity: Exploring Colors in Nature

As the spring season makes its arrival, you’ll begin to notice the world around you growing more colorful – from green buds appearing on trees and plants to the sky boasting bright shades of blue to the vibrant flowers starting to bloom.

With this fun activity, you can explore the vivid side of nature by using chromatography science to examine the colors found in leaves and flowers.

Materials Needed:

• Glass jars
• Mortar and pestle (or a bowl and spoon)
• Paper
• Paper towels
• Pencil
• Rubbing alcohol
• Various leaves and flowers

Step-by-Step Instructions:

1. Head outside to collect various leaves and flowers. Be sure you’re collecting from a spot where you’re permitted to take natural items, like a schoolyard, local park or your own backyard.
    
2. Once you have your collection, sort the leaves and flowers by type. For example, you might choose to sort by color or size.
    
3. Choose one leaf to tear into pieces and crush them using a mortar and pestle, or place the pieces in a bowl and use the back of a spoon to crush them.
    
4. Once the leaf pieces are crushed, move them into a glass jar and add enough rubbing alcohol to fully submerge them.
    
5. Tear a strip from a paper towel and place it inside your jar so the bottom touches the liquid and the top rests over the edge of the jar.
    
6. Clean the bowl you used for crushing your leaf, then choose a flower and take the petals off, tear them into pieces and use your mortar and pestle (or bowl and spoon) to crush them.
    
7. Add the crushed petals to another glass jar and pour enough rubbing alcohol to fully submerge them.
    
8. Place another strip of paper towel in the liquid, resting one end of it on the edge of the jar.
    
9. Check back on the paper towels after 30 minutes and notice what has happened to them.
    
10. Repeat these steps with as many leaves or flowers as you would like and record your observations!

What Are We Discovering?

Chromatography is the process of separating colors to learn more about a substance. In this activity, the colors on your paper towel strips are the pigments from the leaves or flowers you collected. The green color you saw from the leaf is chlorophyll. Plants use chlorophyll to absorb light for energy. What other colors do you see on your paper towel strips? What pigments might you expect to see from leaves in the fall? What other pigments could you extract from nature?

Speaking of colors, did you know that colors can be trademarked? Two National Inventors Hall of Fame^® Inductees, brothers Cyril Keller and Louis Keller, invented the Bobcat® skid-steer loader and helped launch the compact equipment industry. The name Bobcat is a registered trademark of Bobcat Company, and so are the colors of the Bobcat machine!

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