1. 9.1 Waves of the Electromagnetic Spectrum
Essential Questions:
How Does the Sun’s Energy Arrive on Earth?
How Do Electromagnetic Waves Compare?
What Makes Up the Electromagnetic Spectrum?

2. What is a Wave?

3. How Does the Sun’s Energy Arrive on Earth?
An electromagnetic wave is a disturbance that involves the transfer of electric and magnetic energy.
Vibrating electric and magnetic fields that move through space at the speed to light.

4. How Does the Sun’s Energy Arrive on Earth?
This transfer of energy through space or matter is called electromagnetic radiation.
The sun’s energy arrives on Earth as electromagnetic radiation.

5. How Do Electromagnetic Waves Compare?
All electromagnetic waves travel at the same speed in a vacuum, but they have different wavelengths and frequencies.

6. How Do Electromagnetic Waves Compare?
The distance between the crest of one wave and the crest of the next wave is its wavelength.
The frequency of a wave is the number of waves that pass a given point in a certain amount of time.

7. How Do Electromagnetic Waves Compare?
As wavelength decreases, frequency increases.
The higher the frequency of a wave, the higher its energy.

8. What Make Up the Electromagnetic Spectrum?
The complete range of electromagnetic waves is called the electromagnetic spectrum.
Radio Waves
Microwaves
Infrared Waves
Visible Light
Ultraviolet Rays
X-Rays
Gamma Rays

9. Radio Waves Longest wavelength Lowest frequency
A radio converts radio waves into an electrical signal, which is then converted into sound.

10. Microwaves Shorter wavelength than radio waves.
Higher frequency than radio waves.
Used to heat food and transmit communication and radar information.

11. Infrared Rays Shorter wavelength and higher frequency that microwaves.
Often called heat rays since you feel the energy of infrared rays as heat.
IR cameras and heat lamps both utilize IR rays.

12. Visible Light Electromagnetic waves that you can see!!!
Shorter wavelengths and higher frequencies than IR.
Appears as white light, but is actually a mixture of colors that when separated produces the rainbow.

13. Ultraviolet Rays
Shorter wavelength and higher frequency than visible light. Also slightly more energetic.
Extended exposure to these rays can produce sun burns and possibly cancer.
Short exposures allow your skin to produce vitamin D, which is needed for healthy bones and teeth.

14. X-Rays
Shorter wavelength, higher frequency, and more energetic than UV rays.
X-rays can penetrate most matter.
Bones absorb x-rays, which makes them useful in medicine.

15. Gamma Rays
Shortest wavelengths, highest frequencies, and most energy of all electromagnetic waves.
Also useful in medicine in small doses.