• Even in the context of classwork, prisms excite students. Students normally think of white light as being just that--white. Working with prisms can help them understand how light can refract and bend, as well as the fact that it is made up of various colors.
  
  

Learning Through Discovery

• Divide students into groups, and provide each group with a prism, a convex lens, a flashlight, and a piece of white paper. Have students write down their predictions about how they would have to arrange the objects in order to make the strongest rainbow appear. Then have them use the objects to test their predictions. As a class, discuss which of their predictions were right and why.
  
  

Prisms and Rainbows

• Once students understand the basics of how prisms work, help them to infer how a rainbow might be created. Make sure students understand that raindrops can act like prisms. Have them make a large poster, using tagboard and paint, to depict how they think a rainbow is formed. Then encourage them to search on the Internet (or read a chapter in their science books) to confirm or revise their predictions.
  
  

Shapes of Prisms

• Provide each group of students with a rectangular prism and a triangular prism. Instead of shining a light through the prisms, have them look through each of the prisms at text on a piece of paper. Encourage them to discuss how the prism changes the appearance of the text. Then show them how to tilt the prism so that they're not looking at it straight on, and ask them to discuss how that changes the appearance of the text once more. Encourage them to brainstorm explanations for why the refraction of light caused by the prism might make the text appear different when viewed through each prism.