1. Electromagnetic Waves

2.  EM waves – waves that DO NOT need a medium to travel through, they can travel through a vacuum (empty space)  Examples of EM waves: Radio waves – GPS, MRI, RADAR Microwaves – heating up food Infrared waves – heat lamps, warmth Light – what we can see Ultraviolet rays (UV) – causes cancer and vitamin D X-rays – too much exposure can cause cancer Gamma rays – radiation, hulk, nuclear weapons

3. EM Waves  ALL EM waves travel at the speed of light (VERY FAST)  At this speed, they can travel around the would 8 times in one second

4. EM Spectrum  EM Spectrum – range of EM waves from low to high frequency

5. EM Spectrum

6. Longest wavelength Lowest frequency Shortest wavelength Highest frequency

7. EM Spectrum

8. Visible Light  Visible Light – part of the EM spectrum that humans can see

10. R O Y G B I VR O Y G B I V Long wavelength Low frequency Low energy COLD Short wavelength High frequency High energy HOT

11. R O Y G B I VR O Y G B I V  The color you see is the wavelength that is reflected while all other color wavelengths are absorbed  EX: If you see green, that means green is reflected and all other colors are absorbed – plants have chlorophyll

12. R O Y G B I VR O Y G B I V  White is the reflection of all the colors  Black is the absorption of all the colors

13. Questions 1. Which EM wave has the longest wavelength? Radio waves

14. Questions 2. Which EM wave has the highest frequency? Gamma waves

15. Questions 3. What part of the EM spectrum can be seen by humans? Visible Light

16. Questions 4. Visible waves have a higher frequency than what other waves? Radio, Microwave, Infrared waves

17. Questions 5. What color of the visible light spectrum is considered to be the hottest with the highest energy and highest frequency? Violet

18. Questions 6. In a vacuum, all EM waves have the same? A. Wavelength B. Frequency C. Speed of light D. Amplitude

19. Questions 7. In the summer, people use sunscreen to prevent damage to the integumentary system. What type of rays do sunscreen help prevent from penetrating in and damaging your skin? A. Gamma rays B. Ultraviolet rays C. Visible rays D. X-rays

20. Questions 8. EM waves can transfer energy without a? A. Electric current B. Medium C. Magnetic field D. Source