| A | B |
|---|
| density | the amount of matter in a given space |
| volume | the amount of space an object takes up |
| mass | the amount of matter in an object |
| isostasy | the balancing of the downward force of the crust and the upward force of the mantle |
| mantle | the layer of the Earth that extends from the bottom of the crust to the core |
| lithosphere | the topmost solid part of the Earth |
| Pangaea | the single giant land mass that existed more than 200 million years ago |
| crust | the surface layer of the Earth |
| fossil | the preserved remains or traces of an ancient organism |
