4. Which of these terms describes the process of acid rain wearing away limestone?

Acryptic erosion

B. chemical weathering

C. cryptobiotic weathering

D. chemical erosion

B. Chemical weathering

Explanation:

Erosion is the process whereby the soil and rocks are washed away by wind, water, ice or gravity.

Weathering is the process of weakening and breaking down of rocks and minerals either by non-living (abiotic) or living (biotic) factors or by both, such as temperature changes, plants and animals, acids, salts and water, etc.

From the above definitions, it can be seen that acid wearing away limestone is a rock weathering process by a non-living agent, an acid.

Option A is wrong because the process is weathering

Option B is correct because an acid is a chemical and the process involved is weathering

Option C is wrong because an acid is non-living

Option D is wrong because the process involved is weathering