5. The chemical composition of rocks changes when acid is produced by the roots of some plants.

6. Minerals in rocks dissolve.

7. Tree roots can grow into cracks and break rock apart.

8. As the wind blows, it carries sand or small rock particles that scratch the rock's surface.

9. As the rocks expand, the cracks become deeper and new cracks are produced.

10. Rocks exposed to the intense heat of the sun crack and crumble when rain falls or soak in the ground.​