Hands-on Activity Magnetic or Not?

Learning Objectives

After this activity, students will be able to:

• Describe the chemical composition of steel.
• Identify metals that respond to magnets.

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.

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• 1 ceramagnet (a ceramic magnet made of iron, nickel, or beryllium oxides in clay; these are available online from Sargent-Welch and other companies for about $5)
• 1 steel item (anything from the classroom is acceptable; hardware is most relevant to a recycling yard)
• 1 iron item (anything from the classroom is acceptable)
• 1 aluminum item (anything from the classroom is acceptable; soda cans are most relevant to a recycling yard)
• 1 plastic item (anything from the classroom is acceptable; plastic bottles are most relevant to a recycling yard)
• 1 wood item (anything from the classroom is acceptable)
• 1 brass item (anything from the classroom is acceptable; furniture hardware is most relevant to a recycling yard)
• Items composed of other substances that can be found conveniently and at no cost can be added
• Magnetic or Not? Worksheet, one per student

Worksheets and Attachments

Pre-Req Knowledge

An understanding of basic chemical and physical properties of different metals and differences among those properties. Of importance to note specifically of the several metals tested is that steel is a physical mixture of iron and carbon.

Introduction/Motivation

We are testing the usefulness of a magnet for separating steel from aluminum. To start, think back to elementary school when your teacher first gave you a magnet to play with. What do magnets do? (Take answers from students, writing them on the board for future reference. Ask students to clarify or defend statements. Do not acknowledge the correctness of any student who says they attract iron, but do point out the difference between "iron" and "metal.") Based on what you think a magnet does, we are going to make some predictions about a specific set of items that may or may not come through your recycling yard. An engineer designing a system to separate metal would run experiments like this to determine if a magnet can help solve the problem. (Hand out the worksheets to each group and write the list of items on the board.)

Procedure

Setup

• Make copies of the Magnetic or Not? Worksheet, one per student.
• Have ready the required materials for each group, except for the magnet.

With the Students

1. Divide the class into groups of two students each. Hand out the worksheets.
2. Ask students to write the materials in each cell of the column "The material is..." on the worksheet.
3. Ask students to make a prediction of whether or not each material is magnetic and write in the column "I think it is..." if the material is "magnetic" or "not magnetic."
4. Give each group the magnet and have them test their predictions, writing the result in the column "but it really is...."
5. Upon completion of the tests, discuss the results as a whole class. Make the point that steel and iron are magnetic but aluminum is not. Ultimately have students synthesize an individual statement that describes what types of materials are magnetic.

Vocabulary/Definitions

steel: A solid mixture of iron and carbon.

Assessment

Discuss results from experiments relating answers and findings to the grand challenge (separating materials). Have students describe the composition of steel and determine which metals responded to the magnet. Additional assessments are conducted in accompanying lessons 3 and 4.

Troubleshooting Tips

Make sure the materials you choose are actually composed of the desired substances or unexpected attractions may occur if there is significant iron present in the material. Nickel is a good material to add if you can find it, but nickel plated hardware and nickel coins probably do not have enough nickel to be affected by the magnet.

Copyright

Contributors

Supporting Program

Acknowledgements

The contents of this digital library curriculum were developed under National Science Foundation RET grant nos. 0338092 and 0742871. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.