3

• What is a major source of atmospheric pollutants?

  • Combustion of fuels
• What elements are contained in most fuels?

  • Carbon
  • Hydrogen
  • Sulfur (may also contain)
• What gases may be released when a fuel burns in the atmosphere?

  • Carbon dioxide
  • Water (vapour)
  • Carbon monoxide
  • Oxides of nitrogen
  • Solid particles
  • Unburned hydrocarbons
• What is partial combustion?

  When there is not enough oxygen during combustion, some fuel does not burn completely.
• What are the pollutants released during partial combustion?

  Solid particles of soot (carbon), carbon monoxide, and unburnt fuel.
• What is the energy form released during the combustion of hydrocarbons?

  Heat energy is released.
• What are the products formed when carbon and hydrogen in fuels are oxidized during combustion?

  • Carbon dioxide
  • Water
• What are the properties and effects of carbon monoxide?

  • Colourless
  • Odourless
  • Toxic gas
  • Not easy to detect
• What are the environmental and human health effects of sulfur dioxide and oxides of nitrogen?

  • Cause acid rain
  • Lead to respiratory problems in humans
• What effects do particulates have?

  • Cause global dimming
  • Lead to human health problems