Electromagnetic Waves
Electromagnetic Spectrum
Radio Waves f ~ 10 6 Hz – 10 9 Hz λ ~ 300 m – 0.3 m Lowest frequency, highest wavelength Used to transfer information (TVs, Radios etc) Used in astronomy (radio telescopes)
Electromagnetic Spectrum Microwaves f ~ 10 9 Hz – Hz λ ~ 300 mm – 0.3 mm Used to carry long distance telephone conversations Used to cook
Electromagnetic Spectrum Infrared Waves f ~ Hz – 4.3 x Hz λ ~ 0.3 mm – 700 nm Felt as heat Remote controls often use infrared ( λ ~1000 nm)
Electromagnetic Spectrum Ultraviolet Light f ~ 7.5 x Hz Hz λ ~ 400 nm – 3 nm Causes suntans and sunburns (and cancer) Majority of UV rays are absorbed by Ozone (O 3 )
Electromagnetic Spectrum X-Rays f ~ Hz Hz λ ~ 3 nm – nm Used in medicine
Electromagnetic Spectrum Gamma Rays f ~ Hz and higher λ ~ nm and lower Can kill cancer cells and microorganisms in food