LESSON 3 - The Electromagnetic Spectrum

• Be introduced to the Electromagnetic Spectrum.
• Realize that there is energy beyond visible light that we cannot see.
• Identify examples of parts of the EM Spectrum in the Wavestown picture.

Materials Needed:

Prism

Strong flashlight

Wavestown picture (262k) pdf document (1 per student)

Wavestown picture - answer key

Electromagnetic spectrum description worksheet (1 per student)

IMAGERS - Electromagnetic Spectrum Web Site

Digital satellite image Worksheet (18k) pdf document

Digital satellite image Answer key (31k)

Crayons

Ask students "what is light?" White light is all colors, like the colors of the rainbow. Explain that Isaac Newton discovered the color of light by shining white light through a prism. Demonstrate his experiment using a flashlight and a prism. Tell students that this is called the "visible light spectrum." The visible light spectrum is a part of a larger spectrum called the electromagnetic spectrum. Explain that light is energy and that there is energy beyond visible light. In this lesson, they will be studying the electromagnetic spectrum.

Take students to computer lab. Begin on the IMAGERS - Student's Site and select the Electromagnetic Spectrum. Read the first page titled "What are waves?" together. Then, give each student the Wavestown picture. Have students use the electromagnetic spectrum site to help them label examples of the electromagnetic spectrum found in Wavestown. Students should read the description on the site then look for examples in Wavestown. (If access to computer lab is unavailable, use the worksheet provided.)

When students complete this exercise, discuss their answers as a class. Begin with radio waves. Ask students to give examples found in Wavestown. Continue with microwaves and the other wavelengths to gamma rays.

Continue the lesson by giving students the digital satellite image worksheet. Explain that satellites have sensors which can detect infrared energy, a part of the electromagnetic spectrum. Data gathered by these sensors can be used to make images. Images are created using Red, Green and Blue light, similar to the Digital Picture worksheet used in lesson 2. Review the color combinations with them. Have them label the key with the correct color, then complete the picture. Students may complete it for classwork or homework. Review the results in the next lesson. This worksheet reinforces content on remote sensing introduced in the adventure and introduces concepts in Remote Sensing Lesson 4 and 5.

Use the Wavestown picture to assess students’ understanding of the different energies in the electromagnetic spectrum.

• IMAGERS - Electromagnetic Spectrum Web Site - Preview the electromagnetic spectrum web site the day before teaching this lesson. Find objects to represent different electromagnetic energy, i.e. pocket radio, microwave popcorn, remote control, etc.
• Wavestown activity - You may want to review the answers to this activity prior to the lesson because some answers may surprise you.

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