Teach kids about the layers of Earth using only an egg.
Earth's layered structure is a complex point of geological study. Each layer differs greatly in density, mineral composition, and even in how it relates to certain complicated geological processes of our planet. To teach kindergarteners about Earth's layers, however, you don't need to discuss density, minerals or any of the more intricate details. All you really need to help kindergarteners get a basic concept of Earth's layers is an egg.
The Egg Model of Earth
If you do away with the more involved details concerning Earth's inner-workings, you are left with three main points that are simple to teach and equally simple for kids to learn. To illustrate these points, it helps to have them view Earth and its three primary layers---the crust, mantle and core---like an egg. In teaching settings, it may be best to use hard-boiled eggs, as they can be passed around, peeled and used most interactively.
The Crust/Shell
The crust of Earth is like the shell of an egg. They are both the thin, outside layers that ultimately make up only a small portion of their respective spheres. Earth's crust accounts for only 5 percent of the volume of Earth and even includes the ocean floors. Likewise, the shell is the smallest of the egg's "layers" and therefore well-represents Earth's crust. Be sure to let the children know that this is the layer of the planet on which we all live.
The Mantle/Egg-White
Underneath Earth's thin crust lies mantle. Peel away the hard-boiled egg's shell--or have the children do so-- and underneath they will see the egg-white, or albumen. The mantle itself makes up about 80 percent of the volume of Earth, making it the largest of Earth's layers. Likewise, the albumen layer makes up the greatest portion of the egg. It might be a point of interest to let the kids know that earthquakes come from this layer of the Earth.
The Core/Yolk
At the center of Earth, beyond the crust and the mantle, lies the core, which makes up the remaining 15 percent of Earth's volume. By stripping away the egg-whites, and exposing the round, yellow yolk, you can show the children a great representation of Earth's core. An additional fact that might give children an idea about the conditions of Earth's core is the fact that it is about 5,000 to 6,000 degrees C, half as hot as the surface of the sun.
Tags: Earth layers, crust mantle, Earth core, Earth crust, fact that, know that
