Question

mid - term study guide

1. which statement best describes the physical weathering shown by the diagram?

a. enlargement of the cracks occurs because water expands when it freezes.
b. this type of weathering occurs only in bedrock composed of granite.
c. the cracks become wider because of chemical reactions between water and the rock.
d. this type of weathering is common in regions of primarily warm and humid climates.

1. what are the three factors affecting the rates of weathering? describe them.
2. chemical weathering will occur most rapidly when rocks are exposed to the
3. landscapes will undergo the most chemical weathering if the climate is
4. the demonstration shows that powdered limestone reacts faster than a single large piece of limestone of equal mass when both are placed in acid.

Explanation:

37

The diagram shows ice - wedging, a physical weathering process where water seeps into cracks, freezes and expands, widening the cracks. It's not specific to granite (B is wrong), not a chemical reaction (C is wrong), and is common in cold regions not warm - humid ones (D is wrong).

The three factors are rock type (different rocks weather at different rates), climate (temperature and moisture affect weathering), and surface area (greater surface area leads to faster weathering). Rock type determines resistance to weathering. Climate affects chemical and physical weathering processes. Larger surface area exposes more rock to weathering agents.

Chemical weathering is fastest when rocks are exposed to warm, wet conditions. Warmth speeds up chemical reactions and moisture provides the medium for reactions like dissolution and oxidation.

Answer:

A. Enlargement of the cracks occurs because water expands when it freezes.

38