Weathering and Erosion: Chemical Weathering

The video tutorial explains chemical weathering, where the chemical composition of rocks changes due to reactions with air, water, and other substances. Water is a key agent, dissolving minerals and forming acids that accelerate decomposition. Acid rain, caused by air pollution, further speeds up weathering. Oxidation, another weathering type, occurs when oxygen reacts with metals, forming rust. Biological weathering involves living organisms like lichens and plant roots releasing acids that decompose rocks. Chemical and mechanical weathering often work together to break down earth materials.

What is the primary role of water in chemical weathering?

• It provides nutrients for plant growth.

• It dissolves minerals and forms acids.

• It physically breaks rocks apart.

• It prevents oxidation of metals.

How does acid rain form and affect rocks?

• It forms from soil erosion and slows down rock decomposition.

• It forms from water vapor and accelerates rock formation.

• It forms from air pollution and speeds up rock weathering.

• It forms from plant emissions and protects rocks.

What is the process of oxidation in weathering?

• Oxygen dissolves minerals, making rocks softer.

• Oxygen evaporates from rocks, causing them to shrink.

• Oxygen reacts with metals to form new substances.

• Oxygen combines with water to form acids.

How do lichens contribute to the weathering of rocks?

• They absorb water, preventing chemical reactions.

• They physically break rocks apart with their roots.

• They release weak acids that chemically weather rocks.

• They cover rocks, protecting them from weathering.

What is the relationship between chemical and mechanical weathering?

• Mechanical weathering prevents chemical weathering.

• They are unrelated processes that occur independently.

• Chemical weathering always follows mechanical weathering.

• They often work together to break down earth materials.