Earth Science

Surface Processes and Landforms

Chemical Weathering

Study Tip
Think about why the materials used for storage are often waterproof and/or airtight.

What is Chemical Weathering?

  • Chemical Weathering is the form of weathering where a mineral changes into a different type of mineral through chemical reactions.
  • Any mineral created within Earth’s mantle is exposed to high temperatures and it needs to adjust to cooler temperatures once it rises to the surface. Therefore, a series of chemical reactions changes its composition.
Study Tip
Study Tip
The same way a person may cast a shadow over another person when they stand under the sun, planets or celestial bodies that have aligned themselves cast shadows over one another as well.
Think about why the materials used for storage are often waterproof and/or airtight.
  • Clay is one substance formed by chemical weathering. It’s common because it is very stable for silicate minerals.

What are the Different Forms of Chemical Weathering?

Water
Carbonic acid
Oxygen
Water is a polar molecule meaning that it has positive and negative fields that bind to opposite charges. Hydrolysis is the process where water separates a mineral’s ions.
Carbonic acid formed from interaction between CO2 and water. Carbonic acid helps to dissolve rock particles.
Oxidation is a process where O2 reacts with another element Rust is created from the oxidation of iron oxide.

How Do Plants and Animals React to Chemical Weathering?

  • Plants increase the rate of chemical weathering because elements are exchanged once plant roots take in soluble ions.
  • Bacterial decay involves the use of carbon dioxide in respiration.

Does Mechanical Weathering Affect Chemical Weathering?

  • Mechanical weathering increases the rate of chemical weathering because as rock splits, its surface area increases. With more surface area, chemical weathering will have a greater effect on the rock.
Mechanical weathering
Concept Check
  • Describe what chemical weathering is and explain why it exists.
  • Why is water able to cause chemical weathering?
  • Why are plants and animals able to increase the rate of chemical weathering?
  • Explain why mechanical weathering can increase the rate of chemical weathering.