| A | B |
|---|
| Something used to represent an object or an idea | model |
| The outer layer of the Earth | crust |
| The layer below the crust | mantle |
| The layer below the mantle which is made of a solid inner layer and a molten outer layer | core |
| The center of the Earth, made of solid iron and nickel | inner core |
| Help scientists detemine what is inside the Earth | earthquake waves |
| Discovered the first fossil of a dinosaur | Mary Ann Mantell |
| How old a rock is compared to other rocks | relative age |
| A fossil used to determine the relative age of rock | index fossil |
| How old a rock really is | absolute age |
| A common index fossil | trilobite |
| Kinds of fossils | imprint, mold, cast |
| Elements that help determine the absolute age of a rock | potassium and argon |
