The Electromagnetic Spectrum
By: Christopher Wainwright Aaron & Tom Baroni
What is it?
• The electromagnetic spectrum is the complete
spectrum or continuum of light including radio
waves, infrared, visible light, ultraviolet light, X-rays
and gamma rays
• An electromagnetic wave consists of electric and
magnetic fields which vibrates thus making waves.
The Electromagnetic Spectrum
By: Christopher Wainwright Aaron &
Tom Baroni
Nature of Electromagnetic Waves
• They are Transverse waves without a medium. (They
can travel through empty space)
• They travel as vibrations in electrical and magnetic
fields.
• Have some magnetic and some electrical properties to
them.
• Speed of electromagnetic waves = 300,000,000
meters/second (Takes light 8 minutes to move from the
sun to earth {150 million miles} at this speed.)
Waves or Particles
• Electromagnetic radiation has properties of waves but
also can be thought of as a stream of particles.
• Example: Light
• Light as a wave: Light behaves as a transverse wave
which we can filter using polarized lenses.
•
Light as particles (photons)
•
When directed at a substance light can knock
electrons off of a substance (Photoelectric effect)
Wavelength, Frequency and Energy
• Since all light travels at the same speed,
wavelength and frequency have an indirect
relationship.
• Light with a short wavelength will have a high
frequency and light with a long wavelength
will have a low frequency.
• Light with short wavelengths has high energy
and long wavelength has low energy
RADIO WAVES
• A. Have the longest wavelengths and lowest
frequencies of all the electromagnetic waves.
• B. A radio picks up radio waves through an antenna and
converts it to sound waves.
• C. Each radio station in an area broadcasts at a
different frequency. # on radio dial tells frequency.
• D. MRI (MAGNETIC RESONACE IMAGING)
– Uses Short wave radio waves with a magnet to create an
image
Bands of Radio/TV/Microwaves
Microwaves
• Longer than radio, shorter
than light and infrared
• Wavelength 1 x 10 - 4 m to 1 x
10-1 m
• First used in radar, now used
in communication, medicine
and consumer use
(microwave ovens)
Infrared waves
• Invisible electromagnetic waves
that are detected as heat
• Can be detected with special
devices such as night goggles
• Used in heat lamps
• Higher energy than microwaves
but lower than visible light
Visible Light
• The portion of the electromagnetic spectrum that
human eyes can detect
• ROY G BIV (red, orange, yellow, green, blue, indigo,
violet)
• Red is the lowest frequency and violet is the highest
frequency
Ultraviolet waves
• Higher energy than light waves
• Can cause skin cancer and blindness in
humans
• Used in tanning beds and sterilizing
equipment
The Electromagnetic Spectrum
X-Rays
• High energy waves
• First discovered by
Roentgen
• Used in medicine, industry
and astronomy
• Can cause cancer
GAMMA RAYS
• Shorter wavelength and higher frequency than Xrays
• Carry the greatest amount of energy and
penetrate the most.
• Used in radiation treatment to kill cancer cells.
• Can be very harmful if not used correctly.
Test Time
•
1. What is the relationship between
frequency and wavelength?
•
2. What is meant by ‘spectrum’?
•
3. What does ROY G BIV mean?
Now, let’s really think
• 4. Can you actually see x-rays?
– Support your answer.
• 5. Which color is more energetic, red or
yellow?
• 6. Which type of wave travels faster,
gamma or radio?
• 7. Why are microwaves more dangerous
than radio waves?
Answers
• 1. Frequency and wavelength are properties of waves and since speed is
constant for em waves, as frequency increases, wavelength decreases.
• 2. Spectrum is a continuum of all electromagnetic waves
• 3, ROY G BIV is the difference colors of the visible light in order of longest
wavelength to shortest wavelength.
• 4. X-rays can not be seen, only the waves in the visible light portion are
visible.
• 5. Yellow is higher energy than red because it has a shorter wavelength
and higher frequency.
• 6. Both travel at the same speed, 300,000 km/s (all em waves travel at the
same speed)
• 7. Microwaves have a higher frequency than radio and carry more energy.
References
• en.wikipedia.org/wiki/Electromagnetic_spectr
um
• imagine.gsfc.nasa.gov/docs/science/know.../e
mspectrum.html
• hyperphysics.phy-astr.gsu.edu
• science.hq.nasa.gov/kids/imagers/ems/ems.ht
ml
The Electromagnetic spectrum
By Anna Proctor & Lindsey Ferris
What the heck is the electromagnetic
spectrum?!
 The Electromagnetic Spectrum is the range of
all possible frequencies of electromagnetic
radiation, or waves.
 It distributes or absorbs radiation through
different objects.
 The full set of waves that can travel through
space; includes not only visible light but short
waves.
How colors are
used to show the
level of frequencies.
A special device is
used to control the
movement of
electromagnetic
waves. These
waveguides are
typically metalbased lines pitched
at microwave
frequencies to link
connections between
antennas and
receivers. It’s a oneway channel that
picks up signals and
an attenuator keeps
the signals strength
at a constant.
Different types of radiation
 Radio waves are the
longest wavelength in
the electromagnetic
spectrum.
Infra red light is
associated with heat
and things that give off
heat. Ex: TV remote
controls.
Visible light is the only
thing our eyes can
detect in the
Electromagnetic
spectrum.
Ultra-violet light is
made by special lamps
which in other words,
replaces to sun. Ex:
tanning beds.
More types of radiation
Microwaves are
transmitted through
mobile phones.
Gamma rays are the
highest frequency
waves
X-rays are waves used
to inspect luggage at an
airport or to see
through human skin to
their bones.
Measurements of the electromagnetic
spectrum.

The tiniest waves are measured in angstroms, a
unit of length equal to one hundred-millionth of
a centimeter.
 Waves of visible light are measured in
nanometers (nm).
 While waves in infrared to radio are measured
in more familiar meters.
How else can wavelengths be
measured?
The electromagnetic spectrum can be expressed in terms of energy, wavelength, or frequency.
Visible
wavelengths!
Are the only
electromagnetic
waves we can see.
We see these waves
as the colors of the
rainbow. Each color
has a different
wavelength. Red has
the longest
wavelength and
violet has the
shortest wavelength.
When all the waves
are seen together,
they make white
light.
Each color of the rainbow
corresponds to a different
wavelength of the
electromagnetic spectrum.
Color Charts
THIS CHART SHOWS ALL THE
DIFFERENT COLORS AND
HOW THEY ARE IN
RELATION TO ONE
ANOTHER.
A closer look at colors.
 This a picture at normal size, then blown up 200, 400
and 800 times. Most pictures in magazine are made up of
colored dots.
 A magazine printing press usually can only print four
colors: Cyan, Magenta, Yellow, and Black. Our eyes and
brain put colors together from the colored dots.
QUIZ TIMEEE.
QUIZ TIMEEE.
Sources.
http://www.learner.org/teacherslab/science/light/
color/dots/index.html
http://imagine.gsfc.nasa.gov/docs/science/know_l
2/emspectrum.html
http://science.hq.nasa.gov/kids/imagers/ems/ems.
html
 http://home.clara.net/darvill/emag/index.htm