Electro Magnetic Spectrum

University of Alberta observatory domes


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Lesson Plan Three The Electromagnetic Spectrum

Related texts:  

ScienceFocus 9, Unit E, Topic 5: What Channel is That?

Science in Action 9, Unit E, Topic 3: The Spectroscope

Science in Action 9, Unit E, Topic 3.2: Using Technology to See Beyond the Visible

Science in Action 9, Unit E, Topic 1.2: Discovery Through Technology

Learning outcomes*:

*All requirements in this section are quoted directly from the new Science 9 curriculum from Alberta Learning. The full curriculum can be seen here

Key concepts:

Technologies for space exploration and observation (Unit E)
Communication technologies (Unit E)
Forms of energy (D)

Students will:

Describe and interpret the science of optical and radio telescopes, space probes and remote sensing technologies (Unit E)
Explain the role of radio and optical telescopes in determining characteristics of stars and star systems (Unit E)
Identify and correct practical problems in the way a prototype or constructed device functions (Unit D)
Investigate and illustrate the contributions of technological advances-including optical telescopes, spectral analysis and space travel-to a scientific understanding of space (Unit E)
Investigate and describe ways that human understanding of Earth and space has depended on technological development (Unit E)
Work collaboratively on problems; and use appropriate language and formats to communicate ideas, procedures and results (Units C, E)
Work collaboratively in carrying out investigations and in generating and evaluating ideas (all Units)
Conduct investigations into the relationships between and among observations, and gather and record qualitative and quantitative data (all Units)
Analyze qualitative and quantitative data, and develop and assess possible explanations (all Units)

Activity 1 - "Listening" to the Radio

Background information for teachers and students can be found here.

Outline of the Activity

The nature of the electromagnetic spectrum will be explored by using AM and FM radios. Students will listen to and observe the differences between the AM and FM bands during class time and then at night as a homework assignment. Results will be shared the following day in class and the characteristics of the two bands noted. 


Digitally tuned AM/FM radio (provided by Sky Scan project)

6 AM/FM radios with internal speakers. You may need to ask students to bring one in from home.

AM/FM radio. All students are assumed to have access to this equipment at home.

Overhead projector or strong source of light.

Glass prism.


The night before your class, hand out photocopies of the pages on the Electromagnetic Spectrum as a reading assignment for that night. Check your materials list.

In class

Demonstrate the principle of the electromagnetic spectrum by placing a glass prism on an overhead projector. Turn the overhead on so that a rainbow is displayed. The white light of the overhead projector bulb is bent based on the wavelength and frequency of the various component colour bands that make up the white light.

Ask students to discuss what they learned from their reading on the Electromagnetic Spectrum from the previous night noting the key concepts on a black board and relating the prism demonstration to what they read in the article.


  1. Break the class into 6 groups and have each group set up an AM/FM radio. (These same 6 groups need to regroup again to do the Meteor Detection project.)

  2. Switch the radio on and set it to the AM band. Tune the dial to the lowest frequency and then gradually tune the radio up the dial to the maximum noting the changes in the sound between stations, and the quality of the sound that is heard. Count the number of different stations.

  3. Use the same procedure to observe the sound characteristics of the FM band once again noting the sound quality both between stations and when a station is on the air. Count the number of stations.

  4. Have the class come back together to answer the following questions:

How many stations were heard on each band?

What are the characteristics of the sound between the stations on the AM band? On the FM band?

What are the characteristics of the sound of AM vs FM stations?

Why do you think there were differences, if any, between the observations of the the groups?

Homework assignment

Do the radio listening observation at home using the same procedure for the AM and FM bands. Note any differences in the sound characteristics of each band. Once again, count the number of stations on each band to report to class next day.

Read Radio Telescopes and How to Use Your FM Radio to Detect Meteors

Assessment ideas

Have the students hand in their audio observation notes of the AM and FM band from overnight and assess the quality of their observations, the number of characteristics noted for each band, their description of their technique, and any questions they have posed based on their observations.

Copyright 1999-2015 by Sky Scan, Edmonton, Alberta, Canada. 

We gratefully acknowledge the financial support of the 

Edmonton Centre of the Royal Astronomical Society of Canada, Department of Physics (University of Alberta)

and the

Natural Sciences and Engineering Research Council of Canada

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