| A | B |
|---|
| mountains | are formed where two plates collide and push up layers of rocks. |
| plate tectonics | the theory stating that the earth's surface is broken down into plates that move. |
| crust | the top layer of the earth and the coolest layer of the earth. |
| earthquake | moving plates strain against each other and one plate suddenly gives way. |
| mantle | the middle layer of the earth. |
| volcano | one plate is forced under another plate and melted rock erupts. |
| plate | a large section of the earth's surface that is rigid. |
| core | melted iron and nickel. |
| hydrosphere | the lakes, rivers, and oceans on the earth's surface. |
| atmosphere | the layer of gases that surrounds the earth and contains clouds. |
| lithosphere | the layer of earth that homes are built on.- |
