How do plants produce chemical weathering?
A.
They secrete carbon dioxide that combines with water on the rocks and dissolves the minerals in the rocks.
B.
They secrete chemicals that freeze the water within the cracks of the rocks and break down the rocks.
C.
They secrete acids that dissolve the minerals in the rocks.**
D.
They secrete chemicals that allow them to ingest minerals in the rocks.
The correct answer is C. Plants produce chemical weathering by secreting acids that dissolve the minerals in the rocks.
To arrive at this answer, let's go through each option:
A. They secrete carbon dioxide that combines with water on the rocks and dissolves the minerals in the rocks.
While carbon dioxide may combine with water to form a weak acid (carbonic acid), it is the reaction between the plant's secreted acids and the minerals in rocks that causes chemical weathering.
B. They secrete chemicals that freeze the water within the cracks of the rocks and break down the rocks.
This option is not correct. Freezing water within the cracks of rocks leads to physical weathering, not chemical weathering.
C. They secrete acids that dissolve the minerals in the rocks.
This is the correct answer. Plants can secrete weak organic acids like citric acid, malic acid, or oxalic acid that can dissolve minerals in rocks and contribute to chemical weathering.
D. They secrete chemicals that allow them to ingest minerals in the rocks.
Plants do secrete chemicals, such as enzymes, to break down minerals in rocks so they can absorb nutrients. However, this process is not a direct contribution to chemical weathering.
Therefore, the correct answer is C. Plants secrete acids that dissolve the minerals in rocks and contribute to chemical weathering.