Understanding Earth's External Forces

What are the three main types of external forces of Earth?

• Weathering, Erosion, Deposition

• Sedimentation

• Tectonic Activity

• Volcanism

Define weathering in the context of external forces.

• Weathering is the formation of soil from organic matter.

• Weathering refers to the movement of rocks from one location to another.

• Weathering is the process of creating new rocks from minerals.

• Weathering is the breakdown and alteration of rocks and minerals due to external forces.

What is the difference between physical and chemical weathering?

• Physical weathering involves biological processes; chemical weathering is purely mechanical.

• Physical weathering changes the color of rocks; chemical weathering does not affect their structure.

• Physical weathering occurs only in wet climates; chemical weathering happens in dry conditions.

• Physical weathering breaks rocks mechanically; chemical weathering alters their chemical composition.

Give an example of physical weathering and explain it.

• Chemical weathering from acid rain

• Erosion caused by wind

• Frost wedging is an example of physical weathering.

• Soil formation from organic matter

What is exfoliation in terms of weathering?

• Exfoliation is the weathering process where layers of rock peel away due to temperature and pressure changes.

• Exfoliation refers to the erosion of rocks by water flow.

• Exfoliation is the process of adding layers of soil to a surface.

• Exfoliation is the chemical breakdown of minerals in rocks.

Describe the process of freeze-thaw cycles in weathering.

• Freeze-thaw cycles are caused by volcanic activity.

• Freeze-thaw cycles only occur in polar regions.

• Freeze-thaw cycles involve the heating and cooling of air.

• Freeze-thaw cycles involve the repeated freezing and thawing of water in rock cracks, causing weathering and fragmentation.

How does abrasion contribute to physical weathering?

• Abrasion is a process that only occurs underwater.

• Abrasion contributes to physical weathering by wearing down rocks through friction and impact, breaking them into smaller pieces.

• Abrasion causes chemical changes in rocks.

• Abrasion leads to the formation of new minerals.

What role does chemical weathering play in the breakdown of rocks?

• Chemical weathering breaks down rocks by altering their mineral composition through chemical reactions.

• Chemical weathering only affects the surface of rocks without altering their structure.

• Chemical weathering has no effect on the mineral composition of rocks.

• Chemical weathering strengthens rocks by increasing their density.

Explain how temperature changes can lead to physical weathering.

• Temperature changes lead to physical weathering by causing rocks to expand and contract, creating stress that results in cracks and fractures.

• Physical weathering is caused solely by water erosion.

• Temperature changes only affect the color of rocks.

• Temperature fluctuations have no impact on rock structure.

What is erosion and how does it differ from weathering?

• Weathering involves the movement of soil and rock.

• Erosion only occurs in water bodies.

• Erosion is the removal and transport of soil and rock, while weathering is the breakdown of materials without movement.

• Erosion is the same as weathering.