The Cracked Egg
In this experiment, taken from Earthquake Games, students use eggs to simulate the motion of Earth's plates.

You will need:
A hard-boiled egg for each student
Paper towels
Chart paper for writing observations
Markers

Procedure
1. Read a short nonfiction piece about the layers of Earth (core, mantle, crust).
2. Make comparisons between a hard-boiled egg and the Earth (core-yolk, mantle-white, crust-shell).
3. Introduce the concept of tectonic plates, then instruct students to lightly crack their egg shells until they have some small and some large "plates".
4. Discuss movement of tectonic plates due to forces within Earth.
5. Demonstrate how students can use their thumbs to create pushing, pulling, and sliding forces with their egg shell. Give them time to try out these forces.
6. On chart paper, list some of the results reported by students. Then ask them to describe Earth landforms that are similar in shape to what they saw with their eggs. Make sure to cover mountain formation, subduction (one plate sliding over another), and the breaking away of pieces caused by friction.

Fun Observations
When I boiled eggs for my class, I boiled some a bit too vigorously and a few cracked open. I showed these to my class and they were excited to predict why this happened. They came to the conclusion that these eggs were hotter than the others, producing more pressure than the shells could withstand. They especially enjoyed examining an egg that had burst open and had cooked egg white mounded in a very volcano-like eruption!