How do Trees Breathe Science Experiment for Kids

Learning about trees? Complete your photosysthesis science experiment with this simple science demonstration on how trees breathe.

It’s the perfect addition to your spring STEM activities!

Related: Science Experiments for Kids

HOW TREES BREATHE

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

THE SCIENCE OF PHOTOSYNTHESIS

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 visulized in water because the oxygen gets trapped under the water and makes bubbles.

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What Plants Produce the Most Oxygen?

This science experiment was authored and run entirely by my fourth grader.

Supplies

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

Conducting the Experiment

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.

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.