| A | B |
|---|
| grain | The smallest piece of a mineral in a rock. |
| fossils | Often found in sedimentary rocks which enables scientists to learn about existing life in the past. |
| rocks | Solid material made from minerals that form the earth's crust. |
| rock cycle | the way that rocks change from one form to another. |
| sediment | Bits of weathered rocks and minerals, pieces of dead plants and animals, sand and silt. |
| sedimentary rocks | Rocks formed when sediments are pressed or cemented together. |
| igneous rocks | A rock formed from magma that has cooled and hardened. |
| metamorphic rocks | rock formed when igneous or sedimentary rock is changed by heat or pressure. |
| mineral | a natural, nonliving solid with a definite chemical structure. |
| weathering | The process that breaks down and changes rocks. |
| erosion | the moving of weathered rock and soil. |
| deposition | the dropping of materials moved by erosion. |
| plate tectonics | a theory stating that the earth's surface is broken into plates that move. |
| plate | a large section of the Earth's surface made of the crust and rigid top part of mantle |
| plate boundaries | the edges of plates; where plates meet |
| sequencing | putting in correct order |
| theory | a hypothesis supported by scientific evidence or observations. |
| atmosphere | the layer of gases that surrounds the planet |
| hydrosphere | the water part of the Earth's surface. |
| lithosphere | the rigid outer shell of the earth. |
| crust | the top layer of the Earth above the mantle. |
| mantle | the middle layer of the Earth, between crust and core. |
| core | the center part of the Earth, beneath the mantle |
