II . Identify the change happening in each situation. Write PW for physical weathering and CW for chemical weathering. 8. A boulder on the shore is slowly broken apart by the force of water. 9. Rocks have small crevices in which seeds may fall and grow into big plants. 10. Earthworms make tunnels in the ground which may lead to the breakdown of stones and rocks. 11. Carbonic acid is formed from water mixing with carbon dioxide.
12.
The chemical composition of rocks changes when acid is produced by the roots of some plants.​