What is chemical weathering?

• A. Mechanical breakdown
• B. Breakdown through chemical reactions
• C. Erosion
• D. Deposition

Answer: (B)

Chemical weathering is the breakdown and alteration of rocks through chemical reactions, often involving water and gases in the environment. This changes the minerals themselves, not just their physical size. For example, water can react with feldspar to form clay minerals, iron-bearing minerals can oxidize to form oxides, and dissolving rocks like limestone occurs when acidic water dissolves calcite. These processes release ions into solution and contribute to soil formation. Rate varies with climate and conditions: warm, wet climates speed it up, while cold, dry ones slow it down. Erosion and deposition are about moving and depositing material, not chemically changing the minerals, which is why chemical weathering is distinct.