Electromagnetic waves exist in a continuous spectrum of wavelengths and frequencies. This spectrum of waves is subdivided into regions with familiar names such as radio waves, microwaves, infrared waves, visible light waves, ultraviolet waves, X-ray waves, and gamma ray waves. These regions are ordered according to their wavelength, frequency and energy as follows.

The longer-wavelength regions are those that are located on the left side of the diagram. Frequency and energy vary inversely with wavelength. And so the regions located furthest to the right include the highest frequency and highest energy waves. The first activity in this Concept Builder focuses on these relationships.

The visible light region of the electromagnetic spectrum consists of waves that are detectable by the human eye. The various wavelengths are perceived as different colors by the eye-brain system. These colors and their ordering are often remembered by the mnemonic ROYGBIV; the letters stand for different colors like red, orange, yellow, green, blue, (indigo,) and violet. Their ordering according to wavelength, frequency, and energy is depicted in the graphic below.

The second activity in this Concept Builder focuses on the relationship between the color and their wavelength, frequency, and energy.


This Concept Builder was intended as an in-class activity. It consists of two separate activities - Electromagnetic Spectrum and Visible Light Spectrum. Those two activities are differentiated as follows:
 

• Electromagnetic Spectrum: Question Groups 1-6 ... Learners order the regions of the EM Spectrum according to their wavelengths, frequencies, and energies.
• Visible Light Spectrum: Question Groups 7-12 ... Learners order the colors of the Visible Light Spectrum according to their wavelengths, frequencies, and energies.

Teachers using the Concept Builder with their classes should preview the activity (or view the Questions in the separate file) in order to judge which activity would be most appropriate for their students. 

In order to complete an activity, a student must correctly analyze each question in that activity. If a student's analysis is incorrect, then the student will have to correctly analyze the same or very similar question twice in order to successfully complete the activity. This approach provides the student extra practice on questions for which they exhibited difficulty. As a student progresses through an activity, a system of stars and other indicators are used to indicate progress on the level. A star is an indicator of correctly analyzing the question. Once a star is earned, that question is removed from the que of questions to be analyzed. Each situation is color-coded with either a yellow or a red box. A red box indicates that the student has incorrectly analyzed the question and will have to correctly analyze it twice before earning a star. A yellow box is an indicator that the question must be correctly analyzed one time in order to earn a star. Once every question in an activity has been analyzed, the student earns a trophy which is displayed on the Main Menu. This system of stars and trophies allows a teacher to easily check-off student progress or offer credit for completing assigned activities.

The most valuable (and most overlooked) aspect of this Concept Builder is the Help Me! feature. Each question group is accompanied by a Help page that discusses the specifics of the question. This Help feature transforms the activity from a question-answering activity into a concept-building activity. The student who takes the time to use the Help pages can be transformed from a guesser to a learner and from an unsure student to a confident student. The "meat and potatoes" of the Help pages are in the sections titled "How to Think About This Situation:" Students need to be encouraged by teachers to use the Help Me! button and to read this section of the page. A student that takes time to reflect upon how they are answering the question and how an expert would think about the situation can transform their naivete into expertise. 

 

 

There are a few resources at The Physics Classroom website that serve as very complementary supports for the Spectrum Concept Builder. These include:
 

• Reading:
  Most students will find that  Lesson 2 of the Light Waves and Color Chapter of the Tutorial is a perfect accompaniment to this Concept Builder. In particular, the following page will be helpful:
  
  Electromagnetic and Visible Light Spectrum
  
  
   

• Minds On Physics Internet Modules:
  The Minds On Physics Internet Modules include a collection of interactive questioning modules that help learners assess their understanding of physics concepts and solidify those understandings by answering questions that require higher-order thinking. Assignment LC1 of the Light and Color module is a great complement to this Concept Builder. They are best used in the middle to later stages of the learning cycle. Visit the Minds On Physics Internet Modules.
  
  Users may find that the App version of Minds On Physics works best on their devices. The App Version can be found at the Minds On Physics the App section of our website. The Light and Color module can be found on Part 5 of the six-part App series. Visit Minds On Physics the App.
  
   

Additional resources and ideas for incorporating the Spectrum Concept Builder into an instructional unit on Light and Color can be found at the Teacher Toolkits section of The Physics Classroom website.  Visit Teacher Toolkits.