Y9 Electromagnetic spectrum

• Wave speed = frequency x wavelength
• All the elements of the em spectrum travel at the same speed in a vacuum. It includes:

  radiowaves (longest wavelength)

  microwaves

  infrared

  visible light (red with longest wavelength and violet with shortest)

  ultraviolet

  X-Rays

  gamma rays (highest frequency)
• Radiowaves are used for broadcasting and communications
• Microwaves are used for cooking and satellite transmissions
• Infrared is used for heaters and night vision equipment
• Visible light is used for optic fibres and photography
• Ultraviolet is used for florescent lamps
• X rays are used for observing the internal structure of objects and materials, including medical applications
• Gamma rays are used for sterilising food and medical equipment
• When exposed to these electromagnetic waves, it can be detrimental to health, such as:

  • microwaves - internal heating of body tissue
  • infrared - skin burns
  • ultraviolet - damage to surface cells and blindness
  • gamma rays - cancer and mutation