INFORM students of important content or activity instructions.

Introduce the concepts of frequency and wavelength as they relate to the EM Spectrum. See Fundamentals of Remote Sensing Tutorial for more information, section 1.2.

OR

Have students read information on-line about the EM Spectrum (http://imagers.gsfc.nasa.gov/ems/ems.html).

Divide your students into groups and assign each group one of the following forms of EM radiation: radio, microwave, infrared, visible, ultraviolet, x-rays, and gamma. Brief descriptions of each can be found at NASA's Observatorium. (http://observe.arc.nasa.gov/nasa/education/
reference/emspec/emspectrum.html) You may want to print them out, cut printout into individual topics, and distribute to students.

Teacher note: 

1. When you use the above website in the classroom, make sure students click on wavelength (http://observe.arc.nasa.gov/nasa/education/
   reference/emspec/wavelength.html) before reading about the EM types on the page.
2. Have the students complete the Activity sheet: How does remote sensing work? (RSS-2) (See Activity sheet: How does remote sensing work? (RSS-2 below) during this part of the activity.

After students read and become familiar with their assigned form of EM radiation, you may want to have them share with each other the important characteristics of each. Have them focus on information such as whether or not we can see or feel their form of radiation, examples of it from their everyday experience, where it might come from, etc

Ask for representatives of each assigned form of EM radiation to participate in a physical activity demonstrating the characteristics of their energy form.

• Students line up from lowest to highest frequency. 
• Students line up from shortest to longest wavelength. 
• In either case they could role-play higher frequency by shaking or jumping faster or slower and they could role-play wavelength with objects of varying lengths. (These concepts can also be demonstrated quite effectively with a slinky. A piece of rope is also effective and will not get kinked-up like a slinky sometimes does.
• Another option: Students could be paired and assigned one form of EM Radiation. In the "role play" activity each could be assigned either frequency or wavelength. In this way each student gets to line up.

Ask what do all of these forms of EM radiation have in common, i.e. how are they similar?

Ask how do these forms of EM radiation differ?

Optional student activity:

• Review EM Spectrum (http://imagers.gsfc.nasa.gov/ems/ems.html) web-site.

Student activities:

• Break into groups assigned to one form of EM radiation.
• Read about their assigned form of EM radiation.
• Students complete the Activity sheet: How does remote sensing work? (RSS-2) (See Activity sheet: How does remote sensing work? (RSS-2 below) during this part of the activity.

• Share what you learned with the class or a few classmates.
  
  
  
  
  
• Learn the difference between frequency and wavelength and how they help to describe EM radiation.

Optional student activity:

• Participate in a slinky or rope demonstration of the relationship between frequency and wavelength.

Sample student responses:

• Similarities:
• They are all forms of EM radiation.
• They all involve waves, frequency, and wavelength.
• They can travel from source to observer (e.g. across a vacuum, through air, through water) without source and observer actually touching.
• Differences:
• They have different characteristics, i.e., they can do or are used for different purposes.
• Some we can see or feel, some we can't.
• The frequencies and wavelengths are different for different types of EM radiation.

High frequency goes with short wavelength and low frequency goes with long wavelength.