University of Virginia
Physics Department

Electromagnetic Spectrum

A Physical Science Activity

2003 Virginia SOLs

• PS.1
• PS.9

Objectives

Students will

• compare and contrast the regions of the electromagnetic spectrum;
• conduct research to gather information on uses of the electromagnetic spectrum;
• classify common uses of the electromagnetic spectrum into regions.

Motivation for Learning

Driving Question

What is the electromagnetic spectrum? Obtain a large display Electromagnetic Spectrum from a science supplier or put the nice picture shown below in the Student Activity (from Lawrence Berkeley Lab website) up on a screen using a video projector to project your computer screen. Discuss several of the different sources of electromagnetic radiation. The students will probably be surprised to learn that television waves, radio waves, microwaves, visible light, radar waves are actually all exactly the same thing. We can describe them by their wavelength, frequency, or energy, and they are different only by these numerical values. However, their properties are different simply because of these values. A television wave will pass through the walls of our house, whereas visible light will not. Visible light and radio waves pass through Earth's atmosphere, whereas x-rays don't.

You may want to look through the various websites given below in the student activity as an inspiration to begin this activity. There are several nice sites, and if you have the ability to project a computer screen on a large room screen, this would be a useful activity.

Background Information

Electromagnetic radiation (of which visible light is a part) is produced from vibrating electric charges in atoms. The energy travels as a transverse wave that is partly electric and partly magnetic. Other forms of electromagnetic radiation are radio waves, microwaves, and X-rays. The electromagnetic spectrum is the range of electromagnetic waves and ranges from radio waves to gamma rays. The differences among these wave classes rest in their frequencies (and thus their wavelengths). All of them travel at the same speed (3.0 x 108 m/s) in a vacuum.

Student Activity

Materials

• Large piece of white or light colored bulletin board paper
• Markers, crayons, and/or colored pencils
• Glue
• Scissors

Procedure

1. Mark regions on the large piece of bulletin board paper to correspond to the regions of the electromagnetic spectrum (figure 1).

 Figure 1: from Lawrence Berkeley Lab website

2. Divide students into small groups corresponding to the regions of the spectrum. Assign each group a region to research. They should locate the frequency range, wavelength range, sources of the waves, and applications of the spectrum in that region. The groups should then display their research on the bulletin board paper in the appropriate region by drawing or pasting pictures and including data they deem important. Listed below are some suggested websites to research the electromagnetic spectrum. Go through magazines to find applications of electromagnetic waves in your region. If magazines are not available, this could be a homework assignment.
3. When completed, display the poster on the classroom walls to remind students of the large range and many uses of the electromagnetic spectrum.
4. Each group should make a report on their region of the electromagnetic spectrum giving sources and applications.

Websites

Extensions

1. Research the historical nature of the names of the parts of the electromagnetic spectrum.
2. Research telescopes that gather data at different parts of the electromagnetic spectrum.

Students with Special Needs

No special adaptations should be required.

Assessment

1. The accuracy and completeness of the groups' regions on the overall poster can serve as an evaluation of their understanding.
2. Students list appliances in their homes that use portions of the electromagnetic structure. They should then identify the region of the appliance (the actual operating frequency for many appliances is available on the appliance.)