WA.4. Earth and Space Science
ES2. Earth Systems, Structures, and Processes
4-5.ES2. Formation of Earth Materials: In prior years, students learned that water plays an essential role in Earth systems, including shaping landforms and weather. In grades 4-5 students learn how Earth materials change and how they can be used for various purposes. They learn that Earth materials include solid rocks and soil, water, and gases of the atmosphere. People use many of these materials as resources to meet their needs. One of the most important Earth resources is soil, since people depend on fertile soil to grow food. The processes that produce soils offer an excellent opportunity for students to understand how Earth materials change gradually over time, and provide a solid grounding for later study of landforms and large-scale changes of Earth's surface that students will learn in middle school.
4-5.ES2A. Students know that earth materials include solid rocks and soil, water, and gases of the atmosphere. Materials have different physical and chemical properties which make them useful in different ways. Earth materials provide many of the resources that humans use.
4-5.ES2A.2. Students are expected to explain how the properties of an Earth material make it useful for certain purposes, but not useful for other purposes (e.g., rocks are heavy and strong so they are good for building walls, but they are not as useful as lighter materials for roofs).
4-5.ES2B. Students know that weathering is the breaking down of rock into pebbles and sand caused by physical processes such as heating, cooling, and pressure, and chemical processes such as acid rain.
4-5.ES2B.1. Students are expected to describe and give examples of the physical and chemical processes of weathering of rock.
4-5.ES2C. Students know that erosion is the movement of Earth materials by forces such as wind, moving water, ice forming, and gravity.
4-5.ES2C.2. Students are expected to identify local examples where erosion has occurred and describe the most likely cause of the erosion.
4-5.ES2F. Students know that erosion plays an important role in the formation of soil, but too much erosion can wash away fertile soil from ecosystems and farms.
4-5.ES2F.1. Students are expected to explain the role that erosion plays in forming soils and how erosion can also deplete soils.