ELECTROMAGNETS
Grades 3-5

In this lesson students will be participating in video learning and hands-on activities involving electromagnets. Students will construct electromagnets, use them to experiment and collect data, and then use graphing skills to communicate with others.

Classroom Contact #19: More Power to You
Electricity and Magnetism #5: Generation of Electricity
Electricity and Magnetism #4: Measuring and Using Electricity

Students will be able to:

• observe the relationship between electricity and magnetism
• use electricity to produce magnetism by building an electromagnet
• collect and graph data.

• 1 D-cell battery for each child or group of 2 to 4 students
• 1 nail for each child or group of 2 to 4 students
• Pre-cut bell wire for each child or group of 2 to 4 students (cut to lengths of 30 cm, 45 cm, and 60 cm.)
• Small items to be picked up by electromagnets, such as paper clips, straight pins, thumbtacks, or BBs.
• Graph paper for each student

Engage students in a discussion reviewing previous lessons and prior knowledge of how electricity and magnetism seem to be related. Students might respond that both electricity and magnetism involve attraction of unlike charges or poles and repelling of like charges or poles. Some students might mention that electricity can be used to produce magnetism and that magnetism can be used to produce electricity. Tell students that in this lesson they'll be learning more about how electricity can be used to produce magnetism.

INSERT Classroom Contact #19: More Power to You. BEGIN tape at the title "More Power to You." Tell students to watch as Stephanie uses a magnet and wire to produce electricity. To give students a specific responsibility while viewing tell students to raise their hands when they hear the name of a machine used to produce electricity. PAUSE when students raise hands to verify the response "generator." RESUME tape. STOP tape after Stephanie says, "Water from the dam turns the blades of a turbine which turns the coils of wire inside the magnet which generates electricity." EJECT tape.

Engage students in a discussion. How did scientists learn about electricity and magnetism? Do you think humans have always known about electricity and magnetism? How about cave dwellers or early settlers in America? Scientists really began learning about 150 years ago. INSERT tape Electricity and Magnetism #5: Generation of Electricity. Begin tape at visual of Michael Faraday and as narrator says, "In 1831 a scientist named Michael Faraday discovered a relationship between electricty and magnetism." Focus student viewing by telling them to raise their hands when they hear what makes electromagnets special. PLAY tape. PAUSE when students raise hands to verify the response that electromagnets are only magnetic when electricity is flowing. RESUME tape. STOP tape after narrator says, "Electromagnets are used in doorbells, speakers, telephones, and tape recorders to name a few." EJECT tape.

Tell students that now that they have a historical perspective, this last video segment will show them how to build an electromagnet. INSERT Electricity and Magnetism #4: Measuring and Using Electricity. Begin tape at visual of piece of iron and the caption "Not magnetized--domains are scattered and out of alignment." The narrator will say, "This time we're going to use electricity to make our magnet." FOCUS student viewing by telling them to raise their hands when they hear a way to increase the magnetic field surrounding an electromagnet. PLAY tape. PAUSE tape when students raise hands to verify the response that wrapping coils of wire around the nail will cause the magnetic field to be increased. RESUME tape. STOP when narrator says, "That produces the ringing sound we're so familiar with." EJECT tape.

Tell students that now that they have seen electromagnets made in the video they will be using the same materials to build their own electromagnets and using them to collect data which will then be graphed to share with others. Demonstrate for students how to wrap a length or wire around a nail and connect it to a battery. Give students items to pick up with their magnet, such as paper clips, straight pins, thumbtacks, or BBs. Students will wrap each length of wire around the nail and count and record the number of items picked up. Have students predict the number of items that will be picked up before testing each length of wire. Following the tests using all three lengths of wire, students will graph the results. Label graphs with titles. Have groups share graphs and display in classroom. If students have the math ability to average numbers, the students could experiment within groups, report their results to be averaged, compiled and graphed as a class project. Other variables that could be changed in building an electromagnet are the size of the nail and the number of batteries.

Invite an engineer from a company involved in producing telephones, automobiles, or small appliances to explain to students how electromagnets are used in their products. Write or e-mail companies involved in producing telephones, automobiles, or small appliances to request information about how electromagnets are used in their products.

Visit an auto plant (or other site, such as a foundry or steel plant) where electromagnets are used to lift and move heavy objects. Use the Internet or Link 19 to communicate with classes in other areas or countries about places they may have visited or have knowledge of in their area or country.

Contact HSSMTI (High School Science Math and Technology Institute) at the University of Missouri - Kansas City to request a high school student to visit the classroom to demonstrate and lead hands-on activities for students.

Science: Use electromagnets to build electric motors.

Science: Research other electromagnetic energy including radio waves, visible light, X rays, cosmic rays, and gamma rays.

Social Studies: Research the lives and discoveries of Hans Christian Oersted, William Sturgeon, Samuel F. Morse, Michael Faraday, Thomas Davenport, James Clerk Maxwell, Joseph Henry, and Dominique F. Arago.

Language: Have students write about an imaginary machine that would use an electromagnet.

Art: Have students draw or construct a model of their imaginary machine.

Master Teacher: Mary Parker