Oswego City School District
Regents Exam Prep Center: Earth's Interior
A basic overview of the earth's mantle, crust, inner core, and outer core. Also discusses how earthquake waves travel through the Earth.
The Franklin Institute
The Franklin Institute: Earth Bowl
This activity from The Franklin Institute demonstrates the layers of the earth using gelatin, pudding, graham crackers, and a few other items. The students actually construct a representation of the earth that they can eat.