In Investigation One, students explore the chemical and physical weathering of rocks and minerals. During this Investigation, students will:

1. Attempt to physically weather marble chips.
2. Chemically weathered marble chips with hydrochloric acid.
3. Simulate continued chemical weathering on marble by submerging calcium carbonate into hydrochloric acid.

Through these experiments, students should conclude that:

1. Physical and chemical weathering are different. Rocks are physically weathered by breaking them into smaller and smaller pieces. Rocks are chemically weathered when compounds in the rock react chemically with another chemical.
2. Physical and chemical weathering combine to weather rocks as rocks break into smaller pieces, physical weathering exposes more of a rock’s surface to chemical weathering. The combination of the two speeds the overall process of weathering.

In Investigation Two, students analyze several factors of erosion including wind, water, slope, and obstacles. During this Investigation, students:

1. Model the effects of erosion on two different slopes.
2. Observe the effects of erosion when obstacles and vegetation are present.

Through these experiments, students should conclude that:

1. When erosion takes place, the soil is moved from one location to another. If erosion occurs on a slope, the soil will be washed down the slope.
2. Soil from a steep slope will be eroded more than the soil from a less steep slope. Obstacles such as rocks and vegetation will decrease the erosion of soil from the slope.

In Investigation three, students study the various components of soil that result from weathering and erosion. During this Investigation, students:

1. Compare and contrast the appearance of the components of soil such as sand, gravel, and organic material.
2. Use a sieve to separate each component of soil to identify the size and amount of each component in a soil sample.

Through these experiments, students should conclude that:

1. Some components of soil include gravel, organic material, and sand.
2. The different components of soil are different chemically and in size.

This Performance Assessment is designed to allow students to solve a problem using the:

• concepts with which they have become familiar during the previous three Investigations, and
• procedures used during the previous three Investigations.