1. DIRECTIONS: Click on the slide one time to view definition. Click on the slide a second time to view the word.

2. Light A form of radiant, fast moving energy that moves in a wave like motion. We can see part of it.

3. Ray A beam of light energy it travels in a straight line

4. Wave The way that energy moves from one place to an other.

5. Longitudinal Wave The particle vibrates in the same direction as the waves are traveling.

6. Transverse Waves The particles move up and down and the energy travels across the wave.

7. trough The lowest point on a wave

8. Crest The highest point on a wave

9. Wave height The distance from the trough to the crest.

10. Wavelength The distance from one point on a wave to the same point on the next wave Example: From crest to crest From trough to trough

11. Amplitude The distance between the equilibrium and the crest. Crest Equilibrium

12. Transparent This type of MATERIAL YOU CAN SEE THROUGH AND ALLOWS ALL THE LIGHT TO PASS THROUGH.

13. Translucent This material allows some light to pass through, but some light is scattered. You can not see the exact object.

14. Opaque This type of material does not allow any light to pass through it.

15. Absorption All light rays are stopped.

16. Transmission Rays of light pass through

17. Reflection When light bounces back off a smooth object at the same angle at which it is shined at.

18. Refraction Light rays are bent when entering a substance

19. Frequency The number of times a whole wave passes over a given distance in a given time.

20. Electromagnetic Spectrum All types of light energy

21. Radio Waves These waves have the longest wavelengths in the EMS. These waves are used to transmit signals to TVs, cell phones, and radios.

22. Microwaves These rays are in between Radio waves and Infrared. They are used for heating our food.

23. Infrared T hese waves can be found in between microwaves and visible light on the electromagnetic spectrum. Some of them give off heat while others are used in your remote control. These waves are invisible to the human eye.

24. Visible light The form light energy of that we can see. The wave length of visible light is between infrared and x-rays. The order of the colors is red, orange, yellow, green, blue, indigo, and violet. You can remember this as roygbiv.

25. These waves have a shorter frequency than visible light so we can’t see them. They are invisible to the human eye but some insects can see them. They are responsible for our sunburns. Ultraviolet waves

26. X-Rays These are what doctors use to take a picture at a hospital. Because bones and teeth are dense they absorb more of these waves than your skin does. These rays can be shot threw you. They have higher energy and smaller wavelengths than ultraviolet waves.

27. These rays have the shortest wave frequency in the EMS. They can also kill living cells, and that’s the reason why they use these rays to help fight cancer.