The Atmosphere - GCSE Chemistry C1

The Atmosphere - GCSE Chemistry C1

1. Today's Atmosphere

   • Composition
     • 78% Nitrogen
     • 21% Oxygen
     • 0.04% Carbon Dioxide
     • 0.96% Other gases
     • Components of air can be separated by:
       • Fractional distillation of liquid air

2. History of the atmosphere

   • Original atmosphere formed by volcanic activity
     • 4.5 billion years ago
     • Original atmosphere contained
       • Carbon Dioxoide
       • Water vapour
       • Little to no oxygen
       • Small amounts of other gases such as NH3, CH4
     • Earth cooled, water vapour condensed to form oceans
       • Decrease in CO2 levels
         • CO2 dissolved into oceans
         • CO2 incorporated into marine organisms
           • Through food
           • Carbonate rocks
         • Primitive plants photosynthesising
           • 6CO2(g) + 6H2O(l) --> C6H12O6(aq) + 6O2(g)
           • Increase in O2 levels

3. The Atmosphere is still changing due to:

   • (Livestock) Farming
     • Methane
   • Volcanic Eruptions
     • Sulphur dioxide
     • Carbon Dioxide
   • Combustion
     • Carbon Dioxide
   • Deforestation
     • Decrease in photosynthesis
       • More CO2
       • Less O2

4. Global Warming

   • CO2 is a greenhouse gas
     • Absorbs heat, maintains temperature
     • As CO2 levels have increased over the past 200 years, there has been an increase in average global temperature
       • Correlation, but not a causal link
   • Reducing CO2 in the atmosphere
     • Iron seeding of oceans to fertilise phytoplankton
     • Developing means of converting CO2 into hydrocarbons to re-use as fuels
     • Alternative forms of energy productions such as wind farms