Grade Levels: 6-8, 9-12

In this lesson plan, adaptable for grades 6-12, students use an interactive simulation called Bending Light to explore the bending of light between two media with different indices of refraction. Students can experiment with prisms and lenses and apply Snell’s Law at the interface between two media. They can also measure the speed and intensity of the light, and use the wave detector to explore the amplitude and phase of the wave.

Lesson Plan Common Core State Standards Alignments

Lesson Plan Next Generation Science Standards Alignments

Students will:

  1. Verify Snell’s Law through a student developed investigation.
  2. Determine the relationship between the angle of incidence and the angle of reflection experimentally.


  • Computers or other devices with internet access


wave detector, amplitude, phase, bending light, phet sims, refraction, prisms, lenses, science game, snell's law, amplitude, bending light


This lesson plan features an interactive simulation titled Bending Light, developed by our award-winning partner PhET through the University of Colorado Boulder. The simulation invites students to explore how light bends when traveling from one material into another.   

Review the Bending Light Simulation Overview to learn about the sim controls, model simplifications, and insights into student thinking.

Preview and play with the Bending Light sim to plan how you will adapt it to your students’ needs.

Build background knowledge or reinforce topics with these BrainPOP movies: Volume of Prisms, Rainbows, Color, Light, Refraction and Diffraction, Electromagnetic Spectrum, and Waves

Lesson Procedure:

  1. Play one or more of the movies listed in Preparation. Tell students that today they will use a simulation to explore how light bends when traveling from one material into another. Explain that by the end, they will understand how light is reflected and refracted.
  2. Instruct students to open the Bending Light sim and familiarize themselves with the controls and features.
  3. Now have students construct a simple circuit with a batteries, light bulb, and voltage sources. Have them draw their circuits in their notebooks.
  4. Ask students what happens to the reflected and refracted rays as they change the angle of the incident light beam? Then ask what changing the index of refraction do to the refracted and reflected light.
  5. Now tell students to develop an experiment to investigate the relationship relating the angle of the incident light and the reflected light. Include any collected data and a short conclusion.
  6. Next have students develop an experiment that finds a relationship relating the angle of the incident beam to the angle of the refracted beam. They are to develop a method that confirms Snell’s Law.
  7. Students’ summaries are to include the following:
    • description of their process (2-3 paragraphs)
    • collected data
    • a conclusion that connects their data to Snell’s Law
Filed as:  4-PS3-2, 4-PS3-3, 4-PS4-2, 6-8, 9-12, Bending Light, BrainPOP, CCSS.ELA-Literacy.RI.4.7, CCSS.ELA-Literacy.RI.5.3, CCSS.ELA-Literacy.RST.11-12.3