weathering

• What is the difference between mechanical and chemical weathering?

  Chemical weathering breaks down rock by altering its chemical composition, whereas mechanical engineering breaks down rock without altering its chemical composition.
• Give an example of mechanical weathering.

  Freeze-thaw weathering.
• Describe the process of freeze-thaw weathering.

  1. Water enters cracks in the rock.

  2. The water freezes and expands, putting pressure on the rock.

  3. The ice thaws, releasing pressure.

  4. Repeated freezing and thawing causes the rock to break apart.
• Give an example of chemical weathering.

  Hydrolysis.
• Describe the process of hydrolysis.

  1. Some rocks react to water because of the minerals they contain.

  2. Minerals react with the acids in water, making new chemical compounds.

  3. These chemical compounds break down the rock over time.