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. Oxygen in air reacting with iron - content in rocks (oxidation) is a chemical reaction. Option A is physical weathering due to expansion of water on freezing. Option B is physical weathering as plant roots physically break rocks. Option D is physical weathering by wind - erosion.

Answer:

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