1. I. Electromagnetic Waves
     

2. Waves… a review Most waves are either longitudinal or transverse.
Sound waves are longitudinal.
But *all electromagnetic waves are transverse…

3. ? ?
Prompt students to guess what the teal box, then the blue box, is hiding. (Wavelength, Amplitude)

4. When an electric field changes, so does the magnetic field
When an electric field changes, so does the magnetic field. When one field vibrates—so does the other.
RESULT-
An electromagnetic
wave.
Click here Animation: Interaction of vibrating charges

5. A. Electromagnetic waves
Produced by the movement of electrically charged particles
Can travel in a “vacuum” (they do NOT need a medium)
Travel at the speed of
light: 300,000,000 meters/second
(Takes light 8 minutes to move from
the sun to earth {150 million miles}
at this speed.)
(Also known as EM waves)

6. Waves of the Electromagnetic Spectrum
Electromagnetic Spectrum—name for the range of electromagnetic waves when placed in order of increasing frequency
Click here (Animation—Size of EMwaves)
ULTRAVIOLET RAYS
INFRARED RAYS
GAMMA RAYS
RADIO WAVES
X-RAYS
VISIBLE LIGHT
MICROWAVES

7. Wave-particle Duality
Light can behave like a wave or like a particle
A “particle” of light is called a photon

9. Radio waves
Have the longest wavelengths and lowest frequencies of all the electromagnetic waves.
Uses:
TV broadcasting
AM and FM broadcast radio ( each channel is a different frequency)
Cell phone communication
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

10. Microwaves Wavelengths from 1 mm- 1 m Uses: Microwave ovens
Bluetooth headsets
Broadband Wireless Internet
Radar
GPS
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

11. How does a microwave oven work?
Waves transfer energy to the water in the food causing them to vibrate which in turn transfers energy in the form of heat to the food.)

12. Infrared Radiation Wavelengths in between microwaves and visible light
Uses:
Night vision goggles
Remote controls
Heat-seeking missiles
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

13. Visible light
Only type of EM wave able to be detected by the human eye
Violet is the highest frequency light
Red light is the lowest frequency light
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

14. Ultraviolet Shorter wavelengths than visible light Uses: Black lights
Sterilizing medical equipment
Water disinfection
Security images on money
There is one more UV slide…

15. Ultraviolet (cont.) UVA UVB and UVC Energy Highest of UV waves
Lower than UVA
Health risks
Extremely low risk for DNA damage
Can destroy Vitamin A in skin
Can cause DNA damage, leading to skin cancer
Responsible for sunburn
Table will fill in from left to right, top to bottom as you advance through. Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

16. X-rays Tiny wavelength, high energy waves Uses: Medical imaging
Airport security
Inspecting industrial welds
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

17. Gamma Rays Smallest wavelengths, highest energy EM waves Uses
Food irradiation
Cancer treatment
Treating wood flooring
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

18. Using the EM waves to view the Sun
Animation—View a Galaxy at different wavelengths

19. B. They all have different wavelength and different frequencies.
Brief SUMMARY
A. All electromagnetic waves travel at the same speed. (300,000,000 meters/second in a vacuum.
B. They all have different wavelength and different frequencies.
Long wavelength-lowest frequency
Short wavelength highest frequency
The higher the frequency the higher the energy.