C9-Chemistry of the atmosphere

• How does the atmosphere maintain life on earth?

  -Controls what gases are contained within the earth and which are emitted into space

  -This helps to maintain a suitable average temperature for life on earth

  -This is done when the heat (from the sun) reflected to the atmosphere is absorbed by the gases, which causes them to collide and spread this heat out suitably.
• how does sulphur dioxide cause acid rain?

  Reacts with the water in the clouds to form dilute sulphuric acid, which then gets precipitated.
• how can the burning of fossil fuels lead to global dimming?

  -When fossil fuels are combusted (incomplete), they release pollutants and particulates that pollute the atmosphere.

  -These block light from making it past the atmosphere to the earth as the light from the sun is reflected back into space.
• phase 1 of the evolution of the atmosphere

  -Volcanoes released lots of gases into the air (mainly CO2, nitrogen and water vapour), which is what is believed to be how the early atmosphere was created.

  -This atmosphere would have been made up of virtually no oxygen as there were not enough living organisms that could produce oxygen.
• phase 2 of the evolution of the atmosphere

  -Water vapour in the atmosphere eventually condensed to form oceans and other bodies of water.

  -These oceans would have removed a lot of the existing carbon dioxide from the atmosphere as this would dissolve; during this process, carbon precipitates would be formed ,that would turn into sediment on the sea bed.

  -Green plants such as algae would have evolved and also absorbed carbon dioxide through photosynthesis.
• How were sedimentary rocks and fossil fuels formed?

  Organisms and marine life that had died were buried under many layers of sediment, which over time they became compressed and formed sedimentary rocks and fossil fuels.
• Phase 3 of the evolution of the atmosphere

  -Through photosynthesis, green plants and algae produced oxygen.

  -With more oxygen in the atmosphere ,more complex life forms started to evolve.
• Greenhouse effect (how do greenhouse gases keep the earth’s temperature suitable for life on earth?)

  -Greenhouse gases absorb the longer wavelength radiation that gets reflected from and back to the earth by the gases.

  -This radiation is thermal radiation, so when it is absorbed by the atmosphere, this results in warming.
• What affects the amount of greenhouse gases in the atmosphere?

  -Deforestation (reduces the amount of CO2 being taken in, so there is more in the atmosphere)

  -Burning fossil fuels (they contain CO2 so this is released)

  -Agriculture (waste produced from this releases high amounts methane)

  -Creating waste (when waste is decomposed, it releases CO2)
• Effects of climate change

  -Polar ice caps melting due to global warming means that the sea levels rise

  -Changes the rainfall patterns in different areas, so the amount of water in these areas varies greatly

  -Frequency and severity of storms increases

  -Changes in temperature and water available leads to changes in environment, which affects the distribution and population of wild species
• What is a carbon footprint?

  The total amount of greenhouse gases produced by an individual, service, or product.
• Ways to reduce the amount of greenhouse gases emitted into the atmosphere

  -Using renewable resources that don't produce as many greenhouse gases and pollutants

  -Reduce the production of waste

  -Government taxing businesses and companies based on the amount of greenhouse gases they emit, as well as making licenses for producing a certain amount of gases.

  -Using technology that captures CO2 produced by burning fossil fuels before it is released into the atmosphere.
• Increase of nitrogen in the atmosphere

  -Nitrogen is produced by the bacteria causing dead organisms to decay

  -Built up in the atmosphere as it is unreactive