C12: The Earth's resources

• finite


  resources that will run out if we continue to exploit them
• renewable


  resources that can be replaced as we use them
• potable


  water that is safe to drink
• pure


  one substance, pure water contains only water molecules.
• chlorine


  kills microbes in water
• ozone


  kills microbes in water
• ultra violet radiation


  kills microbes in water
• distillation


  a way of obtaining pure water
• reverse osmosis


  an expensive way of removing dissolved salt from water
• desalination


  taking the dissolved salts out of water
• filter


  to separate undissolved materials from water
• anaerobic


  without oxygen
• aerobic


  with oxygen
• smelting


  roasting an ore to obtain a metal, e.g. copper
• electrolysis


  removing a metal from a solution of its salts using an electric current, copper us purified in this way
• displacement


  obtaining a metal from a solution of its salts using a more reactive metal. Copper can economically be displaced from solutions using scrap iron.
• phytomining


  using plants to extract metals like copper from ground that contains metal compounds.
• bioleaching


  using bacteria to extract metals
• life cycle assessment


  looking at the economic and environmental cost of each stage in making a product from obtaining the raw materials to the end of a products life.
• recycle


  to get materials back so that they can be used again, recycling saves on the energy and environmental damage caused by extracting new raw materials.