The Electromagnetic Spectrum

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The Electromagnetic Spectrum

• Kimberly G. Anderson
• Physical Science

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Synonyms

• Electromagnetic waves are formed when an electric
  field (which is shown in blue arrows) couples
  perpendicular to a magnetic field (which is shown
  in red arrows).
• Electromagnetic Energy
• Electromagnetic Spectrum
• Electromagnetic Radiation
• http//www.gallawa.com/microtech/mwave.html

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Facts about the EMS

• Air nor other medium is needed for these waves to
  travel--can travel through a vacuum.
• Exposure to some of these waves is dangerous.
• Has particle-like behavior.
• Photons are tiny, massless bundles of energy
  which cause this radiation to have momentum.

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Some waves are longer than others

• Radio Waves
• Micro Waves
• Infrared Waves
• Visible Light Waves
• Ultraviolet Waves
• X Rays
• Gamma Rays

• Listed in order of the longest wavelength to the
  shortest wavelength.
• As the wavelength gets shorter, the wave gains
  more penetrating power.

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Notice the decreasing wavelength
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Radio Waves

• Radio waves are low energy waves that carry
  information over very long distances.
• Satellite systems
• Cellular phones
• Radio broadcasts
• Cordless phones
• Radio waves are NOT sound waves.

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Microwaves
http//www.gallawa.com/microtech/history.html

• Microwaves are most often used to carry
  energy inside foods items. This energy
  causes the molecules to move very fast, thus
  heating the food.
• Micro waves are used to transmit
• television signals.
• Microwaves are used to send
• radar signals.

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Infrared Radiation
http//www.gemini.edu/index.php?optioncontenttas
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Infrared Radiation is heat.
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Infrared Radiation is used

• By restaurants to keep cooked food hot.
• By police to track running suspects.
• By hunters to see in the dark.
• By insects to track prey.
• for medical imaging.

http//www.x20.org/thermal/pictures4.htm
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Visible Light

• Red Orange Yellow
  Green Blue Indigo Violet
• Visible light is the form of radiation we can
  see.
• Red has the longest wavelength, while violet has
  the shortest.

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Ultraviolet Radiation

• comes from the sun
• is mostly blocked by the ozone layer
• able to energy to penetrate the skin.
• helps skin produce vitamin D, which is needed for
  healthy bones and teeth.
• can over-stimulate melanocytes and cause skin
  cancer.

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UV Radiation is used for

• "sun" tanning
• killing germs
• identification of rocks, gems, and minerals
• the production of ozone (O3)
• disinfecting spa water
• identifying damage and repairs to collectible
  glassware
• identification of counterfeit stamps and bills
• invisible hand stamps for event readmission

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X-Rays

• High penetrating power, can penetrate the soft
  tissues of the body.
• Used for medical imaging
• Elements that give off
• x-rays Molybdenum,
• and some isotopes of
• Cesium and Cobalt.
• Wilhelm Roentgen, 1885,
  Germany

http//www.uhrad.com/kids.htm
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Gamma Rays

• High energy, high penetrating power, very short
  wavelength.
• Originate from the nucleus of an atom.
• Exposure can kill cells
• Used to kill cancer cellsradiation therapy.