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How Do Trees Make Oxygen? Easy Science Project for Kids

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Learning about trees? Complete your photosynthesis science experiment with this simple science demonstration learning how do trees make oxygen. This tree science project teaches the basics of photosynthesis for kids! It is a super easy addition to any elementary science fair project ideas.

In this tree science experiment, kids can figure out whether some trees give off more oxygen than others.

If kids are completing a NGSS science experiment where they must find a solution to a human-created problem, like ozone damage, then they can conduct this experiment to determine what kind of trees would be best to plant to reverse ozone damage.

Keep reading to find out how to set up your own experiment on how plants breathe.

How do trees make oxygen? Learn how in this simple science project for kids. Learn about photosynthesis in a hands on way!

How do Trees Make Oxygen?

Want to know how trees breathe? Complete this tree science experiment and find out which trees produce the most oxygen through photosynthesis.

Photosynthesis for Kids

Photosynthesis is the process of turning sunlight into energy. Chlorophyll within the chloroplasts of plant absorbs light energy.

Chloroplasts store the sun’s energy until it can be used. This energy is then used to split hydrogen atoms from oxygen atoms. Plants absorb carbon dioxide and pairs it with hydrogen molecules to make sure.
The plant consumes the sugar and releases the oxygen back into the air through the leaves. You can see this visualized in water because the oxygen gets trapped under the water and makes bubbles.

What you need for the tree and oxygen experiment:

  • Small containers of similar size (we used mason jars)
  • Several types of leaves (we used leaves from three trees and two bushes)
  • Timer

How Do Trees Make Oxygen Science Experiment

This tree science experiment was authored and run entirely by my fourth grader. She wanted to know if she could tell what trees in our yard produced the most oxygen by figuring out which leaves produced the most bubbles in water.

What Trees Produce the Most Oxygen Experiment Directions

We modified the classic science experiment where you sink a leaf in water to watch how it produces oxygen. When a leaf is submerged, you can see the oxygen it produces in the form of bubbles clinging to the leaves.

Monkey hypothesized that the more bubbles a leaf produced, the more oxygen it could make. We gathered oak leaves, maple leaves, holly leaves, and two mystery leaves- one from a tree and one from a bush.

Learning about trees? This tree unit study is designed to help elementary students learn everything they need to know about trees and photosynthesis!

We placed the leaves in equal amounts of water (about a cup per leaf). We let the leaves sit in the water for one hour.

After an hour, we observed which leaves had the most bubbles. The maple leaf had the biggest bubbles, but the reddish mystery leaves from the bush had the most bubbles. The holly leaves and the mystery tree leaves had almost no bubbles.

Through this experiment, Monkey determined that planting maple trees and the red-leafed bush would produce the most oxygen in any environment. 

This photosynthesis science experiment would also make a great addition to spring science experiments!

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Save this idea for later so you don't forget to use it!