Answer:
The process of breaking down rocks is called weathering. We usually divide weathering into two distinct processes: mechanical, or physical, weathering and chemical weathering. Mechanical weathering breaks rocks into smaller and smaller pieces. Chemical weathering transforms rocks into new substances. Both kinds of weathering take place at or near the earth's surface and are greatly affected by temperature and moisture. The process of weathering usually takes years or even centuries. But slowly, little by little, big rocks are worn away into smaller pieces.
