Introductory Activity :

Duration: Two 45-minute sessions

Description: Students will investigate the effects of different suspended materials and the time it takes for each to become a sediment.

Goals:

1. Students will understand the processes of weathering and erosion.
2. Students will understand that landforms change over time.
3. Students will collect and interpret data to explain an event or concept.
4. Students will know the properties of different types of soil.

Body :

Prior to the lesson, prepare jars with the following (for each small group of students): one containing sand and water, one containing gravel and water, and one containing soil and water. Each jar should have 100 ml of solid and 400 ml of water (depending on the size of the jars).

Students will take turns disturbing the sediment jars by shaking them vigorously for 10 seconds. Students will predict how long it will take the sediment to settle and record their prediction on the data sheet. Then they will use a stopwatch to time how long it takes for the water to clear up. The time should be recorded on the data sheet as well. Then students will shake the sample jar again. Using a flashlight, students will observe how much light can penetrate the sample. Students will classify the amount of light as good, fair, or poor. Students will record their observations on the data sheet. Then students repeat this process for the other two jars.

Discuss the following:

1. Which kind of sediment settled the fastest/the slowest? How did this compare with your estimate for each sample?
2. Which sediment allowed the most light to pass through?
3. Why is it important for light to pass through water?

Inform students that they will be creating their own sediment bottles. (Make sure the labels are removed from the bottles.) Students put a little gravel, sand, and soil into a water bottle. Then they add water to bottle, leaving a little space near the top of it. Then the cap is put on the bottle and sealed with electrical tape. Students shake their sediment bottles and time how long it takes to settle.

Conclusion Activity :

Special Comments: If possible, use large water bottles or plastic jars instead of glass, just in case of breakage.

Vocabulary Words :

• sediment - Matter that settles to the bottom of a liquid.
  
• sedimentation - The process of matter settling to the bottom of a liquid.
  
• erosion - The wearing down of material by various forces of weather, man, or chemical processes.
  
• weathering - Erosion by weather.
  

Evaluation Activity :

Collect students' data sheets. In their journals, students will write a summary of what they learned from the investigation.