Science experiments for kids are big in our home. My kids love them—and so do I. While teaching Kindergarten, I made science experiments a priority. Kids are so naturally curious about the world around them, and science experiments bring this learning fully to life!
This is my ABSOLUTE favourite science experiment of all time—oh yes, I promise it is THAT GOOD!
When asked by my daughter at age 3 (don’t ask me how many years ago that was!), “Why do leaves change colour?” I had no answer.
I looked it up, found it too complicated for a 3-year-old, but explained the best I could and let it be.
I was in Teacher’s College at the time, and wouldn’t you know a few weeks later we learned about—and did—a science experiment for kids about leaves changing colour! It made things so much clearer that I immediately did the experiment with Madeline.
Just before we get started, be sure to download your free printable with step-by-step instructions for this fascinating science experiment!
Please keep in mind this is my (limited) understanding having done the experiment and some research in that class. I’d love to share it with you. So…
Why Do Leaves Change Colour?
Leaves contain Chlorophyll. Chlorophyll makes the leaves green and is so dominant that it covers up all the other colours in the leaves. To figure out what colour a leaf would be without the dominant chlorophyll colour, we can separate the colours by doing this science experiment.
This experiment is very simple and you likely already have everything you need:
- 3 leaves from the same tree
- Rubbing alcohol
- Plastic baggie or plastic wrap
- Paper coffee filter
- Small bowl or pan
1. Have your child break the leaves into tiny pieces and put them in the jar.
2. Pour rubbing alcohol over the leaves until they are just covered.
3. Mash and stir the leaves into the rubbing alcohol until the alcohol turns slightly green. Really give it a good mashing—this is key.
4. Cover the jar with a baggie or plastic wrap. Place the jar in a small bowl and pour hot water into the bowl.
5. Leave (ha!) the jar in the water for 30 minutes, swishing the jar occasionally to stir the leaves a bit. The alcohol should be very dark green (leave longer if needed). If you can resist, wait even 45 minutes or an hour.
6. Cut a strip in the coffee filter so the strip can reach the rubbing alcohol. Place it in the jar like this (we cut a strip off the coffee filter and taped it to the edge of the jar).
7. The liquid will travel up the coffee filter, and the colours will separate as the alcohol evaporates off the coffee filter. Let this happen for about an hour for the full effect. The leaves we used will turn to a beautiful yellow in autumn!
So… Why Do Leaves Change Colour?
In this science experiment, we used rubbing alcohol and energy (hot water) to separate the colours. You likely saw green, and depending on your leaf type, maybe red, yellow, or orange.
As we know, Chlorophyll gives leaves their green colour and is so dominant it hides the other colours in the leaves. But in the fall, chlorophyll in the leaves breaks down allowing the other colours to finally shine through and show their beautiful reds, yellows, and oranges.
I hope your kids love this experiment as much as mine! Science is naturally so hands-on and relevant to kids’ real worlds. Even if your wee one is very little, it may be worth giving this one a go. I did it with my Sammy, and we spaced out the wait time with his rest time. Even though he did not grasp everything, I know he learned a lot!
If you and your little ones love science experiments, I hope you give this cool one a try this Autumn. And if you are not usually one for science experiments, I hope you give this one a try all the same! It really is a game-changer.
Science is everywhere and is such an awesome way to build on children’s natural curiosity about the world.
Thank you so much for reading friends; I hope you are having a wonderful week. I will write you again in a few days!
P.S. Don’t forget to grab your free printable with step-by-step instructions!