Texes Social Studies Content Practice Exam

The process of water freezing inside of a rock, then expanding, and thus cracking the rock is an example of what?

1. Chemical Weathering

2. Transforming

3. Erosion

4. Mechanical Weathering

The correct answer is: Mechanical Weathering

The process described involves water infiltrating the cracks of a rock, freezing and expanding, which leads to the cracking of the rock itself. This is a clear example of mechanical weathering, also known as physical weathering. Mechanical weathering refers to the physical processes that break down rocks into smaller pieces without changing their chemical composition. The expansion of the ice as it freezes exerts pressure on the surrounding rock, causing it to fracture. In this context, the other processes are distinct. Chemical weathering involves the alteration of the rock's chemical structure, often resulting in new minerals, which is not happening here. Transforming does not specifically describe a geological process but may refer to various changes in context. Erosion concerns the movement of sediments and rocks by wind, water, or ice, rather than the breaking apart of the rock itself. Thus, the phenomenon of water freezing and cracking rocks is best classified as mechanical weathering.