1. Chap 10, Sect 2 (Rates of Weathering)
Objectives: (please copy in IAN)
Explain how the composition of rock affects the rate of weathering.
Describe how a rock’s total surface area affects the rate at which the rock weathers.
Describe how differences in elevation and climate affect the rate of weathering.

2. Visual Organizer

3. In this chapter, you will learn about the processes and rates of weathering. Complete this activity to learn about how the size and surface area of a substance affects how quickly the substance breaks down.
Mini Lab Procedure:
1. Fill three small cups about half full with water.
2. Add one sugar cube to one container.
3. Add 1 tsp of granulated sugar to the other container.
4. Try 1 tsp of brown sugar as well!
5. Using one spoon for each container, take turns with your partner and stir the water and sugar in each container at the same rate.
6. Using a stopwatch, measure how long it takes for the sugar to dissolve in each container.

4. Analysis
1. Did the sugar dissolve at the same rate in both containers? Explain why or why not.
2. Do you think one large rock or several smaller rocks would wear away faster? Explain your answer.

6. Weathering takes place on the outer surface of rocks
Weathering takes place on the outer surface of rocks! The more surface area that is exposed to weathering, the faster the rock will be worn down

7. Tech Term:
Differential weathering – the process in which softer, less weather resistant rocks (sedimentary – limestone/sandstone) wear away leaving more weather resistant rocks (igneous – granite/basalt) behind.

8. Weathering and Climate

9. Weathering and Elevation

10. Chemical weathering is faster in _____________
______________
____________
___________of mechanical weathering
_____________,
_____________ thus contributing to ice wedging
___________
_____________are exposed to more wind, water, and ice
________
______________
causes rainwater to flow quickly, increasing the rate of mechanical and chemical weathering
They both affect the rate of _________________weathering

11. Glue and fill in both notes sheets on Weathering!

12. 1. In your own words, develop a definition for the term differential weathering. S6CS10.c
2. A rock will have a lower rate of weathering when the rock S6E5.c
a. is in a humid climate.
b. is a very hard rock, such as granite.
c. is at a high elevation.
d. has more surface area exposed to weathering.
3. How does surface area affect the rate of weathering? S6E5.c
4. How does climate affect the rate of weathering? S6E5.c
5. Why does the peak of a mountain weather faster than the rocks at the bottom of the mountain? S6E5.c

13. Math Skills
6. The surface area of an entire cube is 96 cm2. If the length and width of each side are equal, what is the length of one side of the cube? S6CS3, M6M3.b
Critical Thinking
7. Making Inferences Does the rate of chemical weathering increase or stay the same when a rock becomes more mechanically weathered? Why? S6E5.c