Science Weathering and Erosion Flashcards

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Questions and Answers

Explain the difference between physical and chemical weathering.

Rocks are physically weathered by cracking and then breaking into smaller pieces. Rocks are chemically weathered when a chemical reaction takes place between a rock and another chemical. The difference is that physical weathering is a process that weathers rocks without a chemical reaction or change, while chemical weathering changes the identity of rocks and involves a chemical reaction.

What is a physical property and how does this help you answer the difference between physical and chemical weathering?

A physical property is a characteristic that can be observed without changing the identity of a substance. This helps in answering the difference because physical weathering does not change the substance.

What is a chemical property and how does this help you answer the difference between physical and chemical weathering?

A chemical property is a characteristic that is changed and evident from a chemical reaction. This helps in answering the difference because chemical weathering involves chemical changes.

Explain why 'Rocks and soil are transported from one place to another' more accurately describes erosion than 'Rocks are broken down into smaller pieces.'

'Rocks and soil are transported from one place to another' more accurately describes erosion because it indicates that not only are rocks being broken down, but they are also being moved. Signup and view all the answers

Identify and define the three materials which make up soil.

Humus or other organic materials (big and small chunks of dirt), gravel (hard rock that can be small pebbles), sand (small weathered rock that is usually very tiny pieces). Signup and view all the answers

Explain how growing tree roots cause physical weathering.

Growing tree roots cause physical weathering by growing into rocks and as they grow bigger, they crack the rocks. Signup and view all the answers

Explain how rain causes physical weathering.

Rain causes physical weathering because it carries away rock particles that have been ground off, and when rain falls into cracks of rocks, it can cause freeze thaw. Signup and view all the answers

Explain how freezing and thawing ice causes weathering.

Freezing and thawing ice causes weathering because when water freezes in a rock, it expands and cracks the rock. Signup and view all the answers

Explain why marble gravel would chemically weather faster than a large stone statue and quartz gravel.

Marble gravel would weather faster because it reacts with acid rain. Also, small pieces are more likely to be weathered than larger pieces because more surfaces of the smaller pieces are exposed. Signup and view all the answers

What could Sheila do to reduce erosion around her house on a hill?

Sheila could add trees or other plants to the hill to decrease erosion by slowing the flow of water. She could also add obstacles such as large stones or fences. Signup and view all the answers

How do you know that the particles that make up soil are normally not all the same size?

Soil can be made up of different materials that are different shapes and sizes, including humus, rock particles, gravel, and organic materials. Signup and view all the answers

Circle the sentence that most accurately describes how a sieve analyzes soil. Explain why the incorrect answers are incorrect.

They separate soil by particle size. Signup and view all the answers

State how you know that it may take thousands of years to weather a rock into smaller particles.

I know because when I did a lab about... Signup and view all the answers

Study Notes

Weathering and Erosion Concepts

Physical Weathering: Involves breaking down rocks into smaller pieces without changing their chemical composition. Common causes include growing tree roots, rain, and freeze-thaw cycles.
Chemical Weathering: Alters the chemical structure of rocks, often through reactions with water, acids, or other chemicals. It includes processes that change the identity of the materials.
Difference Highlight: While physical weathering maintains the original rock's identity, chemical weathering changes it through chemical reactions.

Properties Relevant to Weathering

Physical Properties: Observable traits (e.g., size, color) that do not alter a substance's identity; relevant in understanding that physical weathering involves similar non-altering processes.
Chemical Properties: Characteristics that manifest through chemical reactions, indicating changes to the original material; essential in recognizing the effects of chemical weathering.

Erosion Defined

Erosion Process: Described as the transport of rocks and soil from one location to another, emphasizing the movement aspect rather than merely breaking down the rocks.

Soil Composition

Three Materials of Soil:
- Humus: Organic matter that contributes to soil structure.
- Gravel: Coarse material ranging from small pebbles to larger stones.
- Sand: Fine particles resulting from the weathering of rocks.

Factors of Physical Weathering

Tree Roots: As roots grow, they can penetrate and crack rock structures.
Rain: Carries away weathered rock particles and can exacerbate breaking due to freezing when water enters cracks.
Freezing/Thawing: Water expands when frozen, causing pressure and cracks in rocks, leading to weathering.

Chemical Weathering Dynamics

Marble vs. Quartz: Marble weathers faster due to higher reactivity with acid rain; smaller fragments have a larger surface area exposed to weathering agents compared to larger stones.

Erosion Mitigation Strategies

Vegetation: Planting trees and shrubs can reduce erosion due to their ability to slow water flow and stabilize soil.
Obstacles: Using stones or fences can help trap soil and water, diminishing erosion impacts.

Soil Particle Variation

Size Diversity: Soil consists of various materials, leading to a mixture of different sizes and shapes, enhancing its properties.

Sieve Use in Soil Analysis

Sieve Function: Specifically separates soil components by particle size, providing a method for analyzing soil composition.
Incorrect Statements:
- Sieve does not break down soil (A).
- It separates all parts of the soil, not just organic/inorganic (B).
- Does not remove gravel; it separates by size instead (D).

Long-Term Weathering Implications

Time Frame: Weathering processes can take thousands of years, emphasizing the slow nature of geological changes and rock breakdown into smaller particles.

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Description

Explore the key concepts of weathering and erosion through these informative flashcards. Understand the critical differences between physical and chemical weathering, and how these processes shape our geological landscape. Perfect for students looking to reinforce their knowledge in earth science.