Chapter 18 The Electromagnetic Spectrum and Light Name _____________________ Section 18.2 The Electromagnetic Spectrum Period ____________ (pages 529–545) Date _____________ This section identifies the waves in the electromagnetic spectrum and describes their uses. 1. Complete the table for the electromagnetic spectrum. List at least two uses for each kind of wave. The Electromagnetic Spectrum Type of Wave Use #1 Use # 2 The Waves of the Spectrum 2. Is the following sentence true or false? (circle one - If it is false change it to make it true). William Herschel determined that the temperature of colors of light was higher at the blue end and lower at the red end. 3. Herschel’s curiosity led him to conclude there must be invisible ________________________ beyond the red end of the color band. 4. Is the following sentence true or false? (circle one - If it is false change it to make it true). The full range of frequencies of electromagnetic radiation is called the electromagnetic spectrum. 5. Name each kind of wave in the electromagnetic spectrum, from the longest to shortest wavelength. Radio Waves 6. Circle the letter of each way that radio waves might be used. a. x-ray machines b. microwave ovens c. radio technology d. television technology 7. Explain the difference between amplitude modulation (AM) and frequency modulation (FM)? 8. How do microwaves cook food? Infrared Rays 9. Circle the letter of each way infrared rays are used. a. source of light b. to discover areas of heat differences c. source of heat d. to discover areas of depth differences 10. Thermograms show variations in ________________________ and are used to find places where a building loses heat to the environment. Visible Light 11. Each wavelength in the visible spectrum corresponds to a specific frequency and has a particular ___________. 12. Is the following sentence true or false? (circle one - If it is false change it to make it true). One use for visible light is to help people communicate with one another. Ultraviolet Rays 13. Ultraviolet radiation has applications in __________________________ and ________________________. 14. Is the following sentence true or false? (circle one - If it is false change it to make it true). Ultraviolet radiation has a lower frequency that visible light. X-rays 15. Is the following sentence true or false? (circle one - If it is false change it to make it true). X-rays have higher frequencies than ultraviolet rays. 16. How can X-rays produce images of the inside of solid objects (like our bodies)? Gamma Rays 17. Gamma rays have the highest _______________________ and therefore the most _____________________ and the greatest penetrating ability of all the electromagnetic waves. 18. How is gamma radiation used in medicine? Critical Thinking 19. How is the Doppler effect used to detect the speed of a vehicle? 20. Write a paragraph about three different kinds of electromagnetic waves that you will encounter today. Describe the wave in terms of its wavelength and frequency and in terms of how it is used.