CHAPTER 18 Assessment

Reviewing Content

Choose the letter that best answers the question or completes the statement.

1. Electromagnetic waves

   • all have the same wavelength.

   • do not carry energy.

   • can travel through empty space.

   • all have the same frequency.

2. The particle model describes light as

   • a. a stream of photons.

   • an interference pattern.

   • a wave.

   • an electric field.

3. The electromagnetic waves with the highest frequency are

   • a. infrared rays.

   • gamma rays.

   • ultraviolet rays.

   • radio waves.

4. Microwaves and radar are

   • a. infrared rays.

   • X-rays.

   • radio waves.

   • ultraviolet rays.

5. Light that vibrates in only one direction is

   • a. scattered.

   • reflected.

   • refracted.

   • polarized.

6. Objects appear fuzzy through a material that is

   • a. polarized.

   • translucent.

   • transparent.

   • opaque.

7. Combining equal intensities of red light, green light, and blue light makes

   • a. a secondary color.

   • a complementary color.

   • black light.

   • white light.

8. A green object

   • a. absorbs green light.

   • reflects green light.

   • absorbs yellow and blue light.

   • reflects red and blue light.

9. An object that produces its own light is

   • a. luminous.

   • coherent.

   • opaque.

   • translucent.

10. Which type of light bulb uses phosphors?

    • a. neon

    • incandescent

    • tungsten-halogen

    • fluorescent

Understanding Concepts

11. How do electric and magnetic fields interact in an electromagnetic wave?

12. What behavior of light is evidence for a wave model of light?

13. Why are infrared rays useful in search-and-rescue operations?

14. How are ultraviolet rays harmful? How can they be helpful?

15. X-rays can take pictures of your bones but visible light cannot. Explain why.

16. Explain why you can see through the glass walls of the terrarium below.

    

17. How do polarized sunglasses work?

18. What does a prism do to white light?

19. How are the secondary colors of light related to the primary colors?

20. What are complementary colors of pigments?

21. When mixing colors of light, why does combining a secondary color with its complementary color give white light?

22. Explain why fluorescent lights are more efficient than incandescent lights.

23. Explain how laser light is different from ordinary visible light.

24. What is the purpose of halogen gas in a tungsten-halogen lamp?

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