1. Describe 3 types of mechanical weathering?
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Describe 3 types of mechanical weathering?

2. Weathering

3. Brain Pop- weathering

4. Agree or disagree? 1. Weathering is the same as erosion.
2. Humans are the main cause of weathering.
3. Plants can break rocks into smaller pieces.
4. Air and water are present in soil.
5. Soil that is 1,000 years old is young soil.
6. Soil is the same in all locations.

5. Weathering
The mechanical and chemical processes that change objects on Earth’s surface over time
Over thousands of years, weathering can break rock into smaller and smaller pieces, such as sand, silt, and clay.

6. Mechanical weathering
When physical processes naturally break rocks into smaller pieces
The chemical makeup of a rock stays the same
Questions- How does the launch lab demonstrate the mechanical break down of rock?
How does weathering break down or change rock?
How does weathering help produce soil?

7. Causes of mechanical weathering
Thermal expansion
Ice wedging
Abrasion
Plant growth
Animal activity
Questions- How is ice wedging similar to the action of plants?
What is the result of a rock undergoing mechanical weathering?

8. Causes of mechanical weathering SKIT
Groups of 4
10 minutes to come up with a skit that explains your cause
Skit must be 1 minute or less
Which two causes of mechanical weathering are due to biological activity?
Which cause of mechanical weathering is most affected by the force of gravity and the slope of the land?
What is ice or frost wedging?
Besides streams, what other natural elements can cause abrasion?

9. What is the difference between mechanical and chemical weathering?
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What is the difference between mechanical and chemical weathering?

10. How is ice wedging similar to the action of plants?
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How is ice wedging similar to the action of plants?

11. Surface area The amount of space on the outside of an object
When something is broken into smaller pieces, it has a GREATER surface area.
Calculate the surface area to volume ratio for both cubes in figure 1.

12. Calculate the surface area of the following.
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Calculate the surface area of the following.

13. Chemical weathering
Changes the materials that are part of a rock into new materials
These granite obelisks show how chemical weathering can affect some rock.

14. Chemical weathering Water acids oxidation
Most substances dissolve in water.
The small pieces mix with water to form a solution and are washed away from the rock.
Acids increase the rate of chemical weathering
combines the element oxygen with other elements or molecules
The product of oxidation is called an oxide

15. Debate- air vs. water Pairs of 2
Pick a role to play a debate between water and air regarding which is a more powerful agent of chemical weather
Why??

16. What affects weathering rates?
The environment helps determine the rate of weathering.
Mechanical weathering occurs fastest in locations that have a lot of temperature changes.
Chemical weathering is fastest in warm, wet places.
The type of rock being weathered also affects the rate of weathering and determines what kinds of products result.

17. Mechanical and chemical weathering in action
Groups of 3
Materials: 3 antacid tablets and 3 cups with equal amounts of vinegar
Keep one tablet WHOLE
Break another tablet into pieces
Crush the third tablet
Place each sample in a cup with vinegar and observe how long it takes each sample to react completely

18. summary
Weathering is the mechanical and chemical processes that change things over time.
Mechanical weathering does not change the identity of the materials that make up rocks. It breaks up rocks into smaller pieces.

19. Summary
Chemical weathering is the process that changes the minerals that are part of every rock into new materials. Oxidation and reaction with an acid are both examples of chemical weathering.
Dr. Marli Miller/Getty Images

20. What do you think now? Agree or disagree?
1. Weathering is the same as erosion.
2. Humans are the main cause of weathering.
3. Plants can break rocks into smaller pieces.
4. Air and water are present in soil.
5. Soil that is 1,000 years old is young soil.
6. Soil is the same in all locations.

21. How does surface area affect the rate of chemical weathering?
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How does surface area affect the rate of chemical weathering?