Hands-on Activity Permeability Materials Experiment:
What Trickles Down?

Learning Objectives

After this activity, students should be able to:

• Identify different materials based on their level of permeability.
• Identify and explain which materials (permeable vs. impermeable) are better for development or agriculture in various settings (urban vs. rural, coastal vs. inland) and why.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• graduated cylinder
• 4 medium empty steel soup cans with tops and bottoms removed (ask students to bring some from home)
• gravel (enough to fill one soup can 3/4 of the way up)
• sand (enough to fill one can 3/4 of the way up)
• soil (enough to fill one can 3/4 of the way up)
• marbles (enough to fill one can 3/4 of the way up)
• 4 pieces of cheesecloth, cut into squares large enough to cover the bottom of a can plus a little extra
• 4 large rubber bands (big enough to go around a can)
• medium size mixing bowl or small bucket to catch water

To share with the entire class:

• water and sink/drain
• can opener, for the teacher to prepare the soup cans
• extra can, rubber bands, tape/hook, bucket/tray and cheese cloth, for teacher demonstration

Pre-Req Knowledge

Students must be able to calculate fractions and percentages, and use a graduated cylinder.

Introduction/Motivation

Show students a permeability demonstration. Prepare by cutting off the top and bottom ends of a soup can. Then tape or hook the can to the edge of a table with cheesecloth on the bottom, but no material in the can. On the floor under the can, place a bucket or tray to catch the water. For the demonstration, pour the water through and let students see how it falls. Discuss the connection to permeability, that is, how cheesecloth is a good example of permeability.

Procedure

Before the Activity

• Gather materials.
• Use a can opener to remove both ends of all the soup cans.
• Cut out the cheesecloth pieces, making them large enough so each can be attached with a rubber band to the end of an open-ended soup can.
• Lay out all materials for student groups to pick up.

With the Students

• Divide the class into groups of four students each.
• Using the laid out materials, challenge groups to design experiment to determine the relative permeability of each substance (that is, gravel, sand, soil and marbles). Following is an example of an experiment that students might create.

Example Experiment

• Use rubber bands to attach cheesecloth to one end of each of the cans.
• Make sure the open end of the can (without cheesecloth) is facing up and the cheesecloth end is resting on the table.
• Fill each can three-quarters of the way up with the materials: one with gravel, one with soil, one with sand and the other with marbles.
• Make sure each student in the group has his or her own can for the material s/he is assigned.

Steps for Each Can

1. Fill the graduated cylinder with 20 ml water.
2. Hold the can over the empty bowl.
3. Slowly pour the water (through non-cheesecloth end) into the can (make sure can is held over the bowl).
4. Write down observations about permeability and how water traveled.
5. Measure the amount of water that permeated through the can and fell into the bowl.
6. Calculate and record the percentage of the water that permeated in milliliters (ml).
7. Record observations and discuss group conclusions.

Vocabulary/Definitions

permeability: The degree to which water or another liquid is able to flow through a material.

porosity: The ratio of the volume of gaps of a material to the volume of its mass.

runoff: The portion of precipitation on land that ultimately reaches streams, often carrying dissolved or suspended material.

sediment: Material deposited by water, wind or glaciers.

Assessment

Pre-Activity Assessment

• Ask students what they notice when they put water in topsoil vs. sand.
• Ask what they know about the difference between topsoil, sand and gravel and similar substances.

Activity Embedded Assessment

• As students conduct their experiments, have them make lists of what they noticed and wonder about.

Post-Activity Assessment

• Have students list the materials used in order of most to least permeable.
• Give students graph paper and ask them to measure amounts of permeable vs. non-permeable area of their yards at home. Include trees and vegetation.
• Discuss ongoing development areas in town. Ask students to think of possible effects and predict problem areas.

Investigating Questions

• What other materials are permeable?
• What materials are impermeable?
• What are some everyday examples of permeability?
• Who might be concerned about permeability?

Safety Issues

• Have an adult cut the cans smoothly with a can opener before the activity. Alert students to be careful of the sharp can edges.
• Watch that students do not shoot the rubber bands.

Troubleshooting Tips

The students with gravel and fewer marbles may have to use slightly less so the cheesecloth can support the weight of these materials.

Activity Extensions

Add more materials, such as clay.

Experiment with mixtures of materials, such as clay and gravel.

Activity Scaling

• To scale up the assignment, adjust the rate of flow of the water and record observations.
• To scale down the activity, prepare the cans and give students charts to record observations and conclusions.

Copyright

Contributors

Supporting Program

Acknowledgements

This content was developed by the MUSIC (Math Understanding through Science Integrated with Curriculum) Program in the Pratt School of Engineering at Duke University under National Science Foundation GK-12 grant no. DGE 0338262. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.