It’s that time of year again when the leaves change color. What color will those green leaves turn into? If you can’t wait for nature to change the leaves, you can speed up the process with this simple experiment.
Let’s do some science…
What You Need
- 3 green leaves from the same tree
- Glass Jar
- Plastic wrap of a plastic baggie
- Small bowl or pan
- Rubbing alcohol
- Paper coffee filter
- Hot water
Step #1 – Take the three leaves and tear them into small pieces. Place in the jar.
Step #2 – Cover the leaves with rubbing alcohol.
Step #3 – Using a fork, mash up the leaves. Do this until the liquid turns green.
Note: Thoroughly mash the leaves. This is the key to the experiment.
Step #4 – Cover the jar with the baggie or plastic wrap.
Step #5 – Place the jar in the bowl or pan. Add the hot water.
Step #6 – Leave the jar in hot water for at least 30 minutes – 45 minutes to one hour is best.
Note: Give the jar a swirl occasionally to help mix the leaves with the alcohol. You should notice the solution turning a darker green.
Step #7 – Cut a strip from the coffee filter. Remove the plastic and place the strip into the jar. Be sure the filter is reaching the liquid.
Step #8 – Let stand for about an hour.
Notice how the liquid is traveling up the filter? You should see the colors separating as the alcohol evaporates from the filter.
Step #9 – Examine the filter for the true color of the leaves you used.
Now that we know the true color of our leaves, let’s explore why they do what they do.
Why Do Leaves Change Color in the Autumn?
In the summertime, leaves are green because of the chlorophyll found in them – chlorophyll produces food for the trees.
This is done by changing water from the ground and carbon dioxide (a special gas from the air) into glucose (a type of sugar). The process is known as “photosynthesis.”
Because the chlorophyll is so busy feeding the trees, the leaves remain green, hiding their true colors deep within.
How does it work?
Water travels up through the roots of the tree, through the trunk, into the branches. From here, the water moves through tiny tubes found in the stem of the leaves.
As Autumn approaches, the weather turns chilly. The trees realize winter is on its way and begin to get ready. They then produce a thin layer of cells that form over the water tubes in the leaves. This blocks any water from entering.
After the water flow is shut off, the leaves begin to lose their chlorophyll. Over time, this action allows the leaves’ true colors to shine through.
Yellow leaves are filled with a chemical called xanthophyll. Orange leaves are filled with a compound known as carotene (just like in carrots).
Why are some leaves red or purple?
Sometimes sugar will get trapped in the leaves. When this happens, it causes them to change to red or purple.
Autumn colors are fun and science is even more fun!
Did you try our experiment? What did you discover? Tell us in the comments section.