Which statement best describes weathering?

• A. The chemical and physical processes that break down rocks on Earth's surface.
• B. The process of sediments being laid down.
• C. The movement of continental plates.
• D. The generation of electricity from wind.

Answer: (A)

Weathering is the process by which rocks are broken down in place at or near Earth’s surface through both physical forces and chemical reactions. Physical weathering includes things like freeze-thaw, temperature changes, and plant roots that crack rocks, while chemical weathering involves reactions such as oxidation or dissolution that alter the minerals inside the rock. The key idea is that weathering changes the rocks where they sit, producing smaller pieces or altered minerals without moving the material away.

This helps distinguish weathering from other concepts: deposition is about sediments being laid down after erosion, plate tectonics describes the movement of large rock pieces of the Earth's lithosphere, and using wind to generate electricity is about energy production, not rock breakdown.