Question

select the correct answer. which of these actions is an example of chemical weathering? a. freezing water widens the cracks in rocks. b. plant roots force their way into cracks in rocks and break them. c. oxygen in air reacts with iron content in rocks, causing them to change color. d. strong winds peel soft rock away, leaving harder rock behind.

Explanation:

Chemical weathering involves chemical reactions that change the composition of rocks. Option A is physical weathering due to water - ice phase change. Option B is physical weathering by plant roots. Option D is physical weathering by wind abrasion. Option C involves a chemical reaction (oxidation) between oxygen in air and iron in rocks, which is chemical weathering.

Answer:

C. Oxygen in air reacts with iron content in rocks, causing them to change color.