Which weathering process involves chemical changes such as oxidation and reduction?

• A. Mechanical weathering
• B. Chemical weathering
• C. Physical weathering
• D. Organic weathering

Answer: (B)

The correct answer is associated with the processes that involve alterations in the chemical composition of minerals and rocks. Chemical weathering specifically refers to the breakdown of rocks through chemical reactions, which include oxidation and reduction phenomena. For example, when iron in ferromagnesian minerals is oxidized, it converts to iron oxides, leading to a change in the rock's properties. Additionally, minerals can react with water, acids, or carbon dioxide, further enhancing their breakdown through chemical transformations.

In contrast, mechanical weathering focuses on the physical disintegration of rocks without altering their chemical composition, such as through freeze-thaw cycles or abrasion. Physical weathering results in smaller pieces of the same material rather than changing the material chemically. Organic weathering pertains to the effects of organic processes, such as plant roots breaking apart rock structures, but does not primarily involve the chemical changes characterized by oxidation and reduction processes. Thus, the emphasis on these significant chemical reactions makes the identification of chemical weathering as the correct answer clear.