Physical and Chemical Weathering

2. The wearing away of a solid object due to the impact of particles carried by the wind.
4. Animals dig into ground and loosen soil.
7. Cycles of freezing and thawing of water in surface.
11. Rocks breaking apart without changing their chemical composition.
12. The loss of electrons during a reaction by a molecule, atom or ion.
13. A simple slow-growing plant that typically forms a low crusty, leaf like, or branching growth on rocks, walls, and trees.

1. Acidic components, such as sulfuric or nitric acid that fall to the ground from the atmosphere in wet or dry forms.
3. Streaming water weathering down rocks.
5. Elongated forms of various minerals deposited from solution by slowly dripping water.
6. Tiny root hairs seeking out small cracks and pits in rock to grow and expand.
8. Disintegration of rocks caused by chemical reactions.
9. Pits in the ground that form in areas where water gathers without external drainage.
10. The peeling away of sheets of rock millimeters to meters in thickness from a rock's surface.