Ozone Layer

• Ozone Layer


  
  

  • Ozone (O3) is a pale blue gas with a pungent colour
  • Ozone is found in the upper layer of the atmosphere. The atmosphere is a layer of air that surrounds the Earth
  • The ozone layer acts as a barrier to filter out harmful ultraviolet radiation from the sun
• Chlorofluorocarbons


  • Chlorofluorocarbons (CFCs) are compounds containing the elements chlorine, fluorine and carbon
  • used as aerosal propellants and refrigerants
• Depletion of Ozone Layer


  • CFCs cause depletion of the ozone layer

  1. When released into the air, CFC float upwards to the stratosphere
  2. In the presence of sunlight, CFCs decompose to form chlorine atoms ( CFCl3 -> Cl + CFCl2)
  3. Chlorine atoms react with ozone to form chlorine and oxygen (Cl + O -> ClO + O2)

  • loss of ozone and depletion of ozone layer allows ultraviolet radiation to reach the Earth's surface
  • Excessive ultraviolet radiation increases the risk of skin cancer, premature aging of skin and eye damage (cataract)