Electromagnetic Spectrum

• The Electromagnetic (EM) Spectrum is just a name that scientists give a bunch of types of radiation when they want to talk about them as a group.

• Electromagnetic Radiation is energy that does not require a medium.

• The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation.

Electromagnetic Waves

• Do not require a medium;• Capable of transmitting its energy through a

vacuum;• Produced by the vibration of charged particles;• Propagates by the oscillation of both the electric

and magnetic fields which support one another• As the electric field recedes, the magnetic field

increases and vice versa

Electromagnetic Waves

• 300,000,000 meters in one second (3.0 x 108 m/s)  

• Light from the sun reaches the earth in 8 minutes.

• Only visible light

• Why can’t you see the others?– The waves are moving either

too fast or too slow for your eyes to pick them up.

PICTURE TIME…WAVELENGTH AND FREQUENCY

• Transverse waves that have some electrical and some magnetic properties.

What is a prism?

• A triangular shaped translucent object which reflects light

WavelengthR O Y G B I V

• Red longest

• Violet shortest

• There are times when it is easier to understand light as a stream of particles or a RAY

DUAL THEORY OF LIGHTDUAL THEORY OF LIGHT

NOT ALWAYS A WAVE

• When light goes through a filter eliminating some of the waves

Picture time!

• Sunlight• Radio• Infrared• Visible light• Ultra Violet• Television• X-rays• Gamma Rays• Ocean

• Radio

• Infrared

• Visible light

• X Rays

• Gamma Rays

Picture time!

What is Visible light

• Shorter wavelengths and higher frequencies than infrared…

• Colors ROYGBIV

• They are opposites.

• When the wavelength gets bigger, the frequency gets lower….

Electromagnetic Spectrum

Picture time!

Picture time!