1. Weathering

2. Weathering is the process by which natural forces break down rocks.
There are 2 types of weathering:
Mechanical weathering
Chemical weathering

3. 1. Making connections with past learning
We talked about weathering when we learned about about the rock cycle. Weathering is the process by which natural forces break down rocks. On ISN 77 Explain, using full sentences and IQIA, how weathering is connected to the rock cycle. Make sure to include which type of rock is directly involved.

4. 1. Making connections with past learning
On ISN 77 Explain, using full sentences and IQIA, how weathering is connected to the rock cycle. Make sure to include which type of rock is directly involved Weathering creates sediment which is compacted and cemented together to create sedimentary rock.

5. Mechanical Weathering
Mechanical weathering is the breaking up of rocks by physical forces.
There are 4 main types:
Ice wedging
Exfoliation
Plant root growth
Abrasion

6. Ice Wedging
When water freezes, it expands. Water freezes in the cracks and pores of rocks and the force of its expansion is strong enough to split the rocks apart.

7. 2. Making connections with outside of the classroom
Have you ever put a beverage in a can into the freezer and left it? What happens? On ISN 77, Explain how this example is connected to ice wedging. Use full sentences, IQIA.

8. 2. Making connections with outside of the classroom
Have you ever put a beverage in a can into the freezer and left it? What happens? On ISN 77, Explain how this example is connected to ice wedging. Use full sentences, IQIA. A can left in the freezer will expand and eventually explode. This is related to ice wedging because the liquid in the can is like the liquid that is in the cracks of rocks. When the liquid freezes, it expands, forcing anything in the way (the can or the rock) to move or break

9. Exfoliation
The process in which layers or sheets of rock gradually break off due to the expansion of the rock caused by a decrease in pressure.

10. 3. Make connections outside of the classroom
I just bought a face wash that claims to exfoliate my face so I end up with smooth skin. On ISN 77, explain how mechanical weathering exfoliation and the exfoliation of my face are similar.

11. 3. Make connections outside of the classroom
I just bought a face wash that claims to exfoliate my face so I end up with smooth skin. On ISN 66, explain how mechanical weathering exfoliation and the exfoliation of my face are similar. Both exfoliations take layers (of skin or of rock) off of a surface

12. Plant Root Growth
Trees, bushes, and other plants may take root in cracks of rocks. As the roots of these plants grow, they wedge open the cracks.

13. 4. Make connections outside of the classroom
On ISN 77 Explain what is happening in this picture. Be sure to use full sentences, IQIA. Include any vocabulary terms we have discusses thus far.

14. 4. Make connections outside of the classroom
On ISN 77 Explain what is happening in this picture. Be sure to use full sentences, IQIA. Include any vocabulary terms we have discusses thus far. The plant root growth is forcing the sidewalk up and out of the way resulting in cracking

15. Abrasion
The process of wearing down by friction, the rubbing of one object or surface against another.

16. 5. Making connections outside of the Classroom
This is sandpaper. Sandpaper is used to make wood smooth, especially before painting or staining. On ISN 77, Explain how this is connected to the abrasion example

17. 5. Making connections outside of the Classroom
This is sandpaper. Sandpaper is used to make wood smooth, especially before painting or staining. On ISN 77, Explain how this is connected to the abrasion example Sandpaper uses friction to wear down the surface of wood just like mechanical weathering abrasion is when rocks are worn down at their surface by friction

18. Chemical Weathering
The breakdown of rocks by chemical reactions that change the rocks’ makeup, or composition.
There are 2 main types:
Dissolving
Rusting

19. 6. Making connections with prior knowledge
On ISN 77, explain what you know about chemical reactions. How do you think chemical reactions can break down rock?

20. Water is the main cause of chemical weathering.
Dissolving
Water is the main cause of chemical weathering.
Many more minerals dissolve in water that is slightly acidic – like lemonade.

21. 7. Making connections outside the classroom
Imagine you had a sugar cube. If that were to represent a rock, explain in detail how you could use that to demonstrate chemical weathering. Write out the explanation in full sentences, IQIA, on ISN 77

22. Rusting The oxygen in air is also involved in chemical weathering.
Many common minerals contain iron. When these minerals dissolve in water, oxygen in the air and the water combines to produce rust.

23. 8. Making connection outside of the classroom
On ISN 77 explain what happened to this bike (why is it that orange/brown/red color?) What do you think will eventually happen to the chain?