Chemistry of the Atmosphere

• Describe the proportions of Gases in the modern atmosphere

  • 80% Nitrogen
  • 20% Oxygen
  • Small quantities of CO₂, H₂O, and noble gases
• Describe the Earth's early atmosphere and how it was formed?

  • The Earth was hot when it was formed
  • There was significant volcanic activity
  • Gases have been released from these volcanoes
  • Gases include: CO₂, N₂, CH₄, NH₃, H₂O
• How did the amount of oxygen in the atmosphere increase?

  Algae and plants produced the atmospheric oxygen by photosynthesis, which can be represented by the equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ As the amount of oxygen gradually increased, there were more plants producing oxygen.
• How did the amount of carbon dioxide in the atmosphere decrease?

  Some CO₂ was dissolved into the oceans, where it reacted with mineral ions to form insoluble carbonates, or it was taken by animals to become part of the skeleton, when an animal dies this becomes sedimentary rock.

  Some plants used the CO₂ for photosynthesis.
• What is the greenhouse effect?

  Greenhouse gases in the atmosphere maintain temperatures high enough to support life on Earth.

  They allow short wavelength radiation from the sun to pass through the atmosphere to the Earth's surface, but absorb the outgoing long wavelength radiation from the Earth causing an increase in temperature.
• What are three examples of greenhouse gases?

  Water vapour, Carbon Dioxide, Methane.
• Why is the greenhouse effect necessary to maintain life?

  The greenhouse effect is a natural phenomenon. Without it the Earth would be too cold for life to exist.
• How have human activities caused an increase in the greenhouse effect?

  Carbon Dioxide - Burning fossil fuels, Deforestation

  Methane - Cattle farming, decomposition of landfill in landfill sites.
• What are the potential effects of global climate change?

  Rising Sea Levels

  More frequent and severe storms

  Changes in the amount, timing and distribution of rainfall

  Changes to distribution of wildlife species
• What is a carbon footprint?

  The total amount of greenhouse gases emitted directly or indirectly over the whole life cycle of a product.
• What actions can be taken to reduce carbon footprint?

  increased use of alternative energy supplies

  energy conservation

  carbon capture and storage

  carbon taxes and licenses

  tree planting
• What are the problems of reducing carbon footprint?

  Scientific disagreements over causes and consequences of climate change

  lack of public information and education

  lifestyle changes (people don't want to give up luxuries)

  economic considerations

  incomplete international cooperation
• What are the advantages of complete combustion?

  less soot made

  more heat per gram of fuel is released with complete combustion

  poisonous carbon monoxide is not produced with complete combustion
• How is pollution caused by combustion?

  When a fuel burns, the gases released into the atmosphere include, carbon dioxide, water, carbon monoxide, sulphur dioxide and oxides of nitrogen

  Solid particles and hydrocarbons may also be released that form particulates into the atmosphere.
• What are the issues associated with sulfur dioxide and oxides of nitrogen?

  Sulfur Dioxide and oxides of nitrogen cause respiratory issues in humans and Sulfur Dioxide causes acid rain. Acid rain damages plants and buildings.
• What problems do particulates cause?

  Particulates, such as carbon particulates, cause global dimming where the amount of sunlight reaching the Earth's surface is reduced. Particulates cause health problems for humans because of damage to the lungs.