Earth Science

Specific Knowledge Areas:

Structure of the Earth System

Performance Expectations:

• gathering, organizing, and representing data
• formulating conclusions from investigational data
• applying scientific principles to develop explanations and solve new problems

National Science Education Standards:

8 A SI 1: Abilities necessary to do scientific inquiry
1.3 Use appropriate tools and techniques to gather, analyze, and interpret data. The use of tools and techniques, including mathematics, will be guided by the question asked and the investigations students design. The use of computers for the collection, summary, and display of evidence is part of this standard. Students should be able to access, gather, store, retrieve, and organize data, using hardware and software designed for these purposes.

1.4 Develop descriptions, explanations, predictions, and models using evidence. Students should base their explanation on what they observed, and as they develop cognitive skills, they should be able to differentiate explanation from description — providing causes for effects and establishing relationships based on evidence and logical argument. This standards requires a subject knowledge base so the students can effectively conduct investigations, because developing explanations establishes connections between the content of science and the contexts within which students develop new knowledge.

1.5 Think critically and logically to make the relationships between evidence and explanations. Thinking critically about evidence includes deciding what evidence should be used and accounting for anomalous data. Specifically, students should be able to review data from a simple experiment, summarize the data, and form a logical argument about the cause-and-effect relationships in the experiment. Students should begin to state some explanations in terms of the relationship between two or more variables.

8D ESS 1: Structure of the earth system
1.5 Soil consists of weathered rocks and decomposed organic material from dead plants, animals, and bacteria. Soils are often found in layers, with each having a different chemical composition and texture.

(Use the "hot" link on the PALS home page to check the full text of related National Science Education Standards, if desired.)

National Council of Teachers of Mathematics:

CNX3: Understand how mathematical ideas interconnect and build on one another to produce a coherent whole:
Grades 6-8

General Instructions to the Teacher:

This task is designed to take students approximately 10-15 minutes to complete.

Students will be working individually during this exercise.

Students should be ready to work as soon as the period begins. The materials should be set out at each lab station, if possible. A central supply area, if needed, should be easily accessible. All supplies should be clearly labeled.

Materials for "Puddles and Soil":

In preparation for the activity the teacher needs:

• sieve screens
• source of sand and soil

At this station students should have:

• soil sample (2-3 spoonfuls)
• sand sample (2-3 spoonfuls)
• silt sample (2-3 spoonfuls)
• spoons (tbs.)
• stop watch or clock with second hand
• 10 ml graduated cylinder
• funnel (small)
• hand lens
• plastic bottle or cylinder
• filter paper (3 sheets)
• paper towels
• 50-100 ml water container

Advance Preparation:

• Place about 1-1.5 cups of each soil sample in a labeled zip lock bag.
• Do not let soil samples dry out. They should be slightly damp to the touch.
• The sand sample should have approximately all the same sized grains.
• Do not mix two different samples.
• White construction sand works well for this activity.
• Silt samples may be obtained by using the sieve screens, using the finest or second grade materials (0.086-0.014mm)
• Check soil/sand/silt samples to make sure they have different infiltration rates.

Safety:

• Be careful.
• Teachers and students should always exercise appropriate safety precautions and utilize appropriate laboratory safety procedures and equipment when working on science performance tasks.

Extensions/Modifications:

• Students may bring their own samples to test.