1. Chapter 4: Light and Sound
Lesson 3: Light and Electromagnetic Waves

2. A) Electromagnetic Waves

3. a) Electromagnetic waves are radiant energy (traveling in waves)

4. b) Speed of Light is 186,000 miles per second, in a vacuum

5. 2) Radio waves: longest wavelength in the electromagnetidc spectrum
2) Radio waves: longest wavelength in the electromagnetidc spectrum. Are used for radio, TV, WiFi, etc.

6. 3) Microwaves: used by microwave ovens to heat food

7. 4) Infrared: Heat Energy, most object give off energy as infrared
4) Infrared: Heat Energy, most object give off energy as infrared. (Greater than red)

8. 5) Visible light: Red is the longest wavelength and Purple is the shortest wavelength (Roy G. BIV)

9. 6) Ultra Violet (UV): shorter than visible light, honeybees can see in UV light. It can cause skin cancer and sunburns. (below violet)

10. 7) X-rays: short wavelengths that pass the body except bones

11. 8) Gamma Rays: shortest wavelength, high energy used in nuclear technologies

13. B) Reflection and Refraction

14. 1) Reflection is the bouncing of light waves off a surface

15. a) Each color has a different wavelength

16. b) White light is the reflection of all colors

17. c) Black objects absorb all colors. NO color is reflected back .

18. d) Each color only reflects one wavelength. The rest are absorbed
d) Each color only reflects one wavelength. The rest are absorbed. For example blue objects absorb all colors except blue. The bue light is reflected back to us.

19. 2) Refraction is the bending of light waves when it passes from one medium to another

20. a) Example: light passing through a prism, straw in a glass or water

21. C) Transparent, Opaque, Translucent

22. 1) Transparent: medium or substance that light can travel through

23. a) Examples: air, water, clear glass, clear plastics

24. 2) Opaque: Substances that light cannot travel through

25. a) Examples: wood, pottery, bricks, animals, people

26. 3) Translucent: a medium that scatters light as it pass through, so object cannot be seen clearly

27. a) Examples: frosted glass, stained glass, colored plastics