Compare and contrast mechanical and chemical weathering

Compare and contrast mechanical and chemical weathering. What is the importance of each in the breakdown of rocks? What are the processes operating in each?
Describe the factors that affect the rates at which mechanical and chemical weathering break down rocks. How are the two related in the development of spheroidal weathering?
From what you now know about the relationship between weathering and soil profile, consider three areas with different climates: Hawaii (warm and wet), Alaska (cold and wet), and Arizona (hot and dry). Describe the soil profile you would expect in each of the three areas based on the controlling factors of soil development. Speculate about which soil zones would be present and how thick (or relatively thick) might they be?