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Geology Science Fair Project

Freezing Rocks: Mechanical Weathering with Water

Freezing Rocks: Mechanical Weathering with Water | Science Fair Projects | STEM Projects
Have you ever wondered how rocks break down into smaller pieces over time? Try this ice wedging experiment and watch what happens when water freezes inside the plaster of Paris!


The hypothesis is that freezing water will cause the plaster of Paris to crack and break apart, just like ice wedging in nature.

Method & Materials

You will mix plaster of Paris and water, pour it into a cup with a water balloon, let it harden, freeze it overnight, and then observe the cracks and breaks that form. Remember to do a control with a cup of plaster of Paris with a balloon filled with air (no water).
You will need plaster of Paris, water, paper cups, balloons, and a tray to catch any mess.


After freezing the plaster cups, students will observe how the water balloon caused the plaster to crack and break apart, just like ice wedging in nature, a form of mechanical weathering. One interesting observation is that the control cup with a balloon filled with air did not crack or break.

Why do this project?

This experiment is interesting because it demonstrates how mechanical weathering like ice wedging can break down rocks over time. It also allows for hands-on learning and observation.

Also Consider

To vary the experiment, try using different materials such as rocks soaked in water. You could also change the temperature or amount of water used to see how it affects the cracks and breaks that form.

Full project details

You can find additional information and details for this science fair project here. Have fun exploring!

Related video

Hey there! Here are some awesome videos about this science project that we think you'll really like. They're not only super fun, but they'll also help you learn more about the science behind the project. So sit back, relax, and get ready to have some fun!!
Get creative and explore how water can break down rocks with this exciting experiment! Learn how to create a rock using plaster of Paris and a water balloon, and even try a tasty variation with chocolate syrup that turns into a shell!
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