What is weathering and how does it contribute to soil formation?

• A. Weathering is the breakdown of rocks into smaller pieces; mechanical and chemical weathering contribute to soil formation.
• B. Weathering only occurs in outer space.
• C. Weathering is the growth of vegetation.
• D. Weathering is the process of erosion only.

Answer: (C)

Weathering is the breakdown of rocks into smaller pieces and mineral parts. It happens in two main ways: mechanical (physical) weathering, like freezing and thawing, abrasion, or root pressure that physically splits rock; and chemical weathering, where water and other chemicals react with minerals to dissolve or alter them. This process is the first step in soil formation because it creates the mineral particles that mix with organic matter from dead plants and animals. As weathered material accumulates and interacts with living organisms, it forms the familiar layers of soil and provides nutrients that plants can take up. Other statements miss the definition or mix up processes: weathering occurs on Earth, not in outer space; it is not the growth of vegetation; and erosion refers to the removal and transport of weathered material, not its breakdown.