Download Notes-EM

Electromagnetic
Spectrum
What is the
Electromagnetic Spectrum?
The electromagnetic spectrum is the entire
range of radiation.
What is radiation?
Radiation is all energy that is released in
the form of waves (or rays)
Electromagnetic radiation – energy carried through space in the form of
waves.
The EM Spectrum is divided up based on
wavelength….
What are some examples of
radiation?
1. Radio Waves
-Radio waves have the longest wavelengths in the
electromagnetic spectrum. These waves can be longer than
a football field
What are some uses for radiation?
Radio waves are used for…
• Radios and TV’s.
• Garage door openers, alarm systems, radio controlled toys.
What are some examples of radiation?
2. Microwaves
-have wavelengths that can be
- measured in centimeters
-The longer microwaves, those
closer to 30 cm, are the ones which
heat our food in microwave ovens.
-Shorter microwaves are used in remote sensing.
These waves are used for radar like doppler, used
in weather forecasts.
-Invisibility cloak clip
What are some uses for radiation?
Microwaves are used for…
• Communication; Cell Phones, Cable, etc.
• Radars; Doppler weather radar, air traffic control, and radar
guns.
•Navigation; Global Positioning Systems (GPS) use microwaves
•Heating Food
What are some examples of
radiation?
3. Infrared Rays
Infra means below; Infrared
rays have longer wavelengths
than visible red light.
What are some uses for radiation?
Infrared rays are used in…
• Photography - to take pictures where there is no visible
light.
• Night vision goggles.
• Remote controls, burglar alarms.
•Camera - http://www.youtube.com/watch?v=f_CM4nljnrQ
What are some examples of
radiation?
4. Visible Light Rays
The type of radiation that
can be detected by human
eyes.
It contains the colors of
ROYGBIV.
What colors make up
visible light?
Visible Light Rays contain ROYGBIV
•
•
•
•
•
•
•
Red
Orange
Yellow
Green
Blue
Indigo
Violet
What are some examples of
radiation?
5. Ultraviolet Rays
The name means "beyond
violet” since violet is the
color with the shortest
wavelength in the visible
light spectrum.
And, UV has even a
shorter wavelength than
violet!
UV rays from a
tanning bed
What are some uses for radiation?
UV rays are used in…
• Security; to help thwart counterfeiters.
• Forensics; helpful in locating and identifying
bodily fluids (blood)
What are some examples of
radiation?
6. X-Rays
• X-rays can penetrate
most materials except
lead shielding. When they
were discovered, the "X"
stood for "unknown,"
because they were so
mysterious. The name has
been used ever since.
What are some uses for radiation?
X-Rays are used to…
• examine luggage and in airports
• detect structural problems and cracks in
airplanes and bridges
•most common use of x-rays is in medicine and
dentistry
What are some examples of
radiation?
7. Gamma Rays
• Gamma rays are commonly produced by the
radioactive decay of elements.
• Gamma-ray bursts are the most powerful
events in the universe, temporarily outshining
several galaxies and signaling the birth of a
black hole.
What are some uses for radiation?
Gamma Rays are used
• in the sterilization of medical equipment
by killing bacteria.
• to kill bacteria and insects in food
Electromagnetic Radiation
The entire range of radiation includes…
1.
2.
3.
4.
5.
6.
7.
Radio waves
Microwaves
Infrared rays
Visible light rays
Ultraviolet rays
X-rays
Gamma Rays
Electromagnetic Radiation
Radio waves have the longest wavelength and the lowest
frequency.
Gamma rays have the shortest wavelength and the highest
frequency.
Electromagnetic Radiation
With visible light…
Red has the longest wavelength of all the colors.
Violet has the shortest wavelength of all the colors.