What is the difference between erosion and weathering?

• A. Erosion involves movement of rocks, while weathering refers to the breakdown of rocks without movement.
• B. Weathering involves movement, while erosion is breakdown without movement.
• C. Erosion only occurs in rocks near the ocean.
• D. Weathering never changes rock size.

Answer: (A)

The main idea being tested is that weathering and erosion are two separate steps in how rocks break down and move. Weathering is the process that breaks rocks apart in place—through physical actions like freeze‑thaw or abrasion, or chemical reactions like acid rain—without moving the material away. Erosion, on the other hand, involves the transport of those weathered pieces by natural agents such as water, wind, ice, or gravity to new locations.

So the statement that erosion involves movement of rocks while weathering refers to their breakdown in place best captures the difference. The other options don’t fit because weathering can involve changes in rock size and composition in its original spot, erosion isn’t restricted to ocean areas, and weathering does not mean there is never any change in rock size.