What is the process by which rocks are broken down by physical and chemical means?

• A. Erosion
• B. Weathering
• C. Melting
• D. Deposition

Answer: (B)

Weathering is the process by which rocks are broken down by physical and chemical means. Physical weathering splits rock into smaller pieces through frost wedging, abrasion, root growth, or temperature changes, without changing the rock’s chemical composition. Chemical weathering changes the minerals in rock through reactions with water, acids, or gases—like carbonic acid dissolving limestone or iron minerals rusting. This distinction matters because the question focuses on breaking rocks down in place, not on moving the material (erosion), melting the rock, or depositing it elsewhere. Erosion moves the broken pieces, melting turns rock into liquid, and deposition settles materials in new locations.