Soils
Lesson 8
What Is Your Mystery Mixture?
Students have learned how to use a variety of soil tests to identify different properties of sand, clay and humus. Now they apply those tests to analyze a mixture of those components and identify them.
3. Lesson set up and Management
SYSTEMS 1.1-Properties: Understand how properties are used to identify, describe, and categorize substances, materials, and objects and how characteristics are used to categorize living things
GLE 1.1.1 Understand simple properties of common natural and manufactured materials and objects: Sort common materials and objects using a simple property and Identify and describe the differences between common natural and manufactured materials and objects using properties.
GLE 1.1.5 Understand physical properties of Earth materials: Sort rocks based on size, shape, and other physical properties and Explain how some Earth materials are used by living things.
SYSTEMS 1.2-Structures: Understand how components, structures, organizations, and interconnections describe systems
GLE 1.2.3 Know that common materials are made of smaller parts: Sort objects based on component parts and Show that people use magnifiers to observe things they cannot see with their eyes.
INQUIRY 2.1-Investigating Systems: Develop the knowledge and skills necessary to do scientific inquiry.
GLE 2.1.1 Understand how to ask a question about objects, organisms, and events in the environment.
GLE 2.1.2 Understand how to plan and conduct simple investigations following all safety rules.
GLE 2.1.3 Understand how to construct a reasonable explanation using evidence.
GLE 2.1.4 Understand that models represent real objects, events, or processes.
GLE 2.1.5 Understand how to record and report investigations, results, and explanations.
INQUIRY 2.2-Nature of Science: Understand the nature of scientific inquiry
INQUIRY GLE 2.2.1 Understand that all scientific observations are reported accurately even when the observations contradict expectations
INQUIRY GLE 2.2.2 Understand that observations and measurement are used by scientists to describe the world.
INQUIRY GLE 2.2.3 Understand that similar investigations may not produce similar results.
- Simple tests can be performed to identify soil components.
- Test results should be observed, recorded, organized and interpreted to draw conclusions about soil composition.
- Test results can be communicated through writing, drawing, and discussion.
3. Lesson set up and Management
Materials:
Students will conduct several soil tests during this lesson, so allow extra time for materials preparation. There are three different "Mystery Soil Mixtures" that will need to be prepared ahead of time.
Mixture A - two 30 ml cupfuls each of sand, clay, and humus
Mixture B - four 30 ml cupfuls of clay to two 30 ml cupfuls of sand
Mixture C - four 30 ml cupfuls of clay to two 30 ml cupfuls of humus
Observing the mystery mixture with a hand lens. |
The completed settling test on the mystery mixture. |
Student Management:
Students will need access to all the materials they have used in the past seven lessons to perform tests. Sheets 8-A through 8-E in the Soils teacher's manual can provide a more guided experience for students if desired. You may also want to use Alternative Conclusion sheet 8.
The Soils teacher's manual provides a table for quick reference interpreting the soil test results, which is helpful for teachers.
This lesson is an embedded assessment opportunity. Observe students as they proceed through the testing process, and record anecdotal evidence of their progress.
Writing:
Lesson 8 provides an opportunity for students to try their hand (perhaps for the first time) at writing a scientific conclusion. Remember that a well-written scientific conclusion should include a conclusive statement, site data and have explanatory language that connects the conclusive statement to the data.