Why Do Leaves Change Color?

Why do leaves change color?  Find the answer through this fun and fascinating experiment that shows children that different colors are always present in leaves, even though they appear to be only green.  Leaves look green in the summer because chlorophyll, a green compound, dominates the other colors in the leaf.  When autumn rolls around, the chlorophyll begins to break down and the other colors become visible.  This experiment uses rubbing alcohol to break down the chlorophyll, simulating the natural process occurring each fall.  I think Maria Montessori would have approved of this simple experiment:

The teacher must derive not only the capacity, but the desire, to observe natural phenomena. The teacher must understand and feel her position of observer: the activity must lie in the phenomenon.

~Dr. Maria Montessori

THE EXPERIMENT:

Step #1: Gather your materials.  Each child will need 1 green leaf, 1 small glass jar, 1 white coffee filter, rubbing alcohol, scissors, a coin or spoon, tape, and foil/ plastic wrap.

Here are the supplies you will need.

Step #2:  Have the children cut a strip out of the coffee filter, about an inch wide.  Then, cut one end so that it comes to a point.

Make a paper strip with a point at one end.

Step #3:  Place the green leaf onto the filter strip about an inch above the pointed end.  Rub the leaf with a coin or spoon to release the leaf’s color.  You should see a green stain on the paper.

Rub the leaf to release the pigment.

Step #4:  Fill each glass jar with about a quarter inch of rubbing alcohol.  Place your paper strip so that the pointed tip is in the alcohol, but the green coloring is not.

Pour a little rubbing alcohol into each glass.

Step #5:  Use a little tape to secure the paper strip in place.  Cover the glass jars with foil or plastic wrap;  let sit for about a half an hour.

Cover the jars and wait about a half-hour.

 Step #6:  Given time, the alcohol separates the color pigments, all of which were present in the green leaf.  Ours turned out with a lot of yellow, and a tiny bit of orange.  Different leaves will reveal different colored pigments.  What did you find?

The pigments separated to revealed yellow and a smidgen of orange.

 

What colors do you see???

 

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