Science Experiment for Kids: Why Do Leaves Change Colour

Science Experiment for Kids: Why Do Leaves Change Colour

September 22, 2021   /     Banyan Tree Kidz ~   /    0 comments

Kids are naturally curious about the world around them and science experiments help bring this learning fully to life. Hands-on learning is an essential part of young kid’s learning as it helps them critically think and challenge themselves as problem solvers. STEM education involves a lot of hands-on learning which helps young individuals with the skills to succeed and adapt to an ever changing and complex technological environment. Science experiments at home are a fun way to introduce young kids to science who would sometimes tend to see science as an intimidating subject. 


Embrace the gorgeous colour of fall this year by conducting a science experiment that shows the colours leaves turn in the fall and explore the science behind this gorgeous transformation that occurs every autumn. We love a simple science experiment and this fall we explore the big question: Why do leaves change color? 


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 the following science experiment.


For this science experiment for kids, you will need - three leaves from the same tree, rubbing alcohol, a jar, a plastic bag or plastic wrap, paper coffee filter and a small bowl or pan. 


  1. Start the experiment by asking your kid to break up the leaves into tiny pieces and place them into the jar. 
  2. Next, pour some rubbing alcohol over the leaves until they are fully covered. 
  3. Mash and stir the leaves into the rubbing alcohol until the alcohol turns slightly green. Giving the leaves a good mashing is the key.
  4. Then cover the jar with the plastic bag or plastic wrap and place the jar in a small bowl and proceed to pour hot water into the bowl.
  5. Now it’s all a waiting game - leave the jar in the water for 30 minutes, swishing the jar occasionally to stir the leaves a bit. The rubbing alcohol should be a very dark green. If you can be patient with your kids, wait even 45 minutes or an hour.
  6. Cut a strip in the coffee filter and place it in the jar so the strip can reach the rubbing alcohol. 
  7. The liquid will travel up the coffee filter strip 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 turn to a beautiful yellow in autumn and it is truly a beautiful visual.

Leaves are actually more colours than just green but Chlorophyll is so dominant most of the summer that its green colour covers up all the other natural colours in the leaves. We can separate the colours of a leaf by doing this leaf chromatography science experiment. In this science experiment we used rubbing alcohol and two types of energy to separate the colours. We used mechanical energy by ripping up the leaves and mashing them, plus heat energy from the hot water. Look closely at the rubbing alcohol, do you see any other colours in there? Most commonly you will see green, but depending on the type of leaf you may also see purple, red, yellow, or orange.


As we know, Chlorophyll gives leaves their green colour and is so dominant that it hides the other colours in the leaves during the spring and summer. But in the fall, chlorophyll in the leaves breaks down, finally allowing the it’s other natural colours to have their moment in the sun! The beautiful reds, yellows, and oranges might be short lived before the leaves fall to the ground. This year, think about the amazing science behind those changing colours as the trees around you put on their colourful fall displays.


Check our Banyan Tree Kidz’ blog on 8 Fun Fall Science Activities for Preschoolers for more fun activities at home during fall. Stuck at home with nothing to do, and you don’t know how to keep your kids occupied? Get them some DIY learning kits that help in engaging and hands-on learning. Every Banyan Tree Kidz box is crafted after hundreds of hours of research, to make each kit simple and engaging for kids to learn, explore and create.

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