| A | B |
|---|
| Inner Core | A ball of hot, solid metals at the center of the earth. The most dense layer. |
| Outer Core | A layer of hot liquid metals surrounding the inner core. |
| Mantle | Earth's thickest layer, it has a rigid upper portion and a softer, lower portion. |
| Crust | Thin layer that surrounds the earth; home to all life on earth. |
| Lithosphere | The crust and the very top of the mantle together. |
| Asthenosphere | A layer of hot, soft rock in the upper mantle - flows like toothpaste or tar. |
| Tectonic Plates | Large and small rock slabs that make up the lithosphere |
| Continental Drift | The idea that the continents have moved or drifted apart. |
| Pangea | The huge supercontinent formed, when all the continents were once joined together. |
| Mid-Ocean Ridge | underwater mountain ranges |
| Convection Current | The circular motion of energy caused when a hot material rises, cools and sinks, then is heated and rises again. |
| Theory of Plate Tectonics | states that the earth's surface is made of moving plates, which are driven by motions in the mantle and asthenosphere. |
