EM waves

• EM Waves

  • Radio Waves (highest wavelength, lowest frequency)
  • Micro Waves
  • Infrared radiation
  • Visible light
  • Ultraviolet light
  • X-rays
  • Gamma rays (lowest wavelength, highest frequency)

  
• Radio waves

  • Used for communication
• Microwaves

  • Used for communication
  • Used in cooking
  • Penetrates 1cm deep into food, before heating the water molecules in the food, cooking the food
• Infra-red radiation

  • Monitor temperature
  • Eg. Night vision camera
  • Medical imaging
• Ultra violet light

  • Fluorescent lamps
• X-rays

  • Medical imaging
  • Penetrates less dense objects, such as skin, but is absorbed by denser objects such as bones
  • By placing a detector plate behind a patient, and passing X-rays through them, we can produce an image of their bones, with the brighter parts of the image representing bones.
• Gamma rays

  • Sterilising medical instruments
  • They kill microbes (such as bacteria)
  • Sterilising food
  • Cancer treatment
  • Doctors must be careful to avoid damaging healthy cells