1. Electromagnetic Spectrum
Video EM Intro

2. Electromagnetic Spectrum
All electromagnetic waves travel at the same speed, but have different wavelengths and frequencies
Speed = wavelength x frequency
Increase frequency = decrease wavelength
Increase frequency = increase energy
Decrease frequency = increase wavelength

3. Electromagnetic Spectrum
Name for the range of electromagnetic waves when placed in order of increasing frequency
Radio wave – microwaves – infrared rays – visible light – ultraviolet rays – X-rays – gamma rays

4. Radio Waves Long wavelength, low frequency
Waves are sent out and returned to the source
Uses:
Radio: the number on your dial is the frequency

5. Microwaves Shorter wavelength, higher frequency than radio waves
Can pass through glass and plastic
Reflected off metal
Uses:
cell phones, RADAR, MRI

6. Infrared Waves Shorter wavelength, higher frequency than microwaves
Means below red
Snakes can see infrared
Uses:
Heat rays
Heat bulbs
Thermogram
Camera with night detection

7. Visible Light Shorter wavelength, higher frequency than infrared
You can see these
Longest wavelength is red, shortest wavelength is violet
ROY G BIV

9. Visible Light
Primary Colors: three colors used to make any other colors (red, blue, and green)
When combined in equal amounts they will produce white light

10. Visible Light and Color
The color of an object is the color of light it reflects, the other colors are absorbed by the light
Pigments: substances that are used to color other materials, as they are added fewer colors of light are reflected and more are absorbed
When all colors are reflected we see white
When all colors are absorbed we see black
When red, yellow, and blue combine they create black colors

12. Ultraviolet Ray
Shorter wavelength, higher frequency than visible light
Can damage or kill living cells, causing skin cancer or damage to eyes
Bees can see UV Rays
The sun’s emission of ultraviolet rays

13. Ultraviolet Rays Uses: To kill bacteria in hospitals
Small doses are good to acquire vitamin D which is good for teeth and bones
Treats jaundice in newborns
Tanning beds

14. X - Rays Shorter wavelength, higher frequency than ultraviolet rays
Can penetrate most objects, but dense bone and lead
Over exposure can lead to cancer
Uses
in buildings to find cracks, make pictures of bones

15. Gamma Rays Shortest wavelength, with highest frequency
Has the most energy
Most penetrating
Objects in space give off gamma rays, but our atmosphere protects us against them
Uses:
Kills cancer cells and can be used to examine the body’s internal structure
Moon in the
night sky if
you could see
gamma rays