chemistry atmosphere

• What is the proportion of gas in the atmosphere?

  78% nitrogen, 20% oxygen, 1% carbon dioxide and small traces of water vapour
• How was the early atmosphere formed?

  gas released when volcanoes erupted
• What gases did the early atmosphere have?

  mostly carbon dioxide, little oxygen
• What planets was the early atmosphere like?

  Mars, Venus
• What gases did volcanic activity release?

  nitrogen which built up in the atmosphere, water vapour and small amounts of methane and ammonia
• How were oceans formed?

  When water vapour in atmosphere condensed
• Why have carbon dioxide levels decreased?

  carbon dioxide dissolving in sea water, layers of sedimentary compressed to form sedimentary rocks, oil and gas
• What did green plants and algae absorb?

  carbon dioxide to carry out photosynthesis
• What did the shells and skeletons of marine animals contain?

  carbonates from the oceans
• What happened to the carbon taken in from the atmosphere and oceans by the marine animals after they died?

  carbon became locked up in rocks and fossil fuels
• What are examples of fossil fuels?

  coal, crude oil, natural gas
• What are crude oil and natural gas formed from?

  deposits of plankton
• What is coal?

  sedimentary rock that is made from thick plant deposits
• What is limestone?

  sedimentary rock made of calcium carbonate deposits from shells and skeletons of marine organisms
• How did the green plants and algae produce oxygen?

  photosynthesis
• When did algae evolve?

  2.7 billion years ago
• What is a benefit of oxygen levels building up in the atmosphere?

  more complex life e.g. animals could evolve
• When did the atmosphere reach a similar composition to what it is today?

  200 million years ago
• What do greenhouse gases do?

  act as insulating layer in Earth's atmosphere which allows the Earth to be warm enough to support life
• What do all particles absorb?

  certain frequencies of radiation
• What do greenhouse gases not absorb and absorb?

  don't absorb incoming short wavelength radiation from sun but they do absorb long wavelength radiation that gets reflected back off the Earth
• What is the greenhouse effect?

  long wave radiation, which is thermal radiation, warming the surface of the Earth
• What is the effect of deforestation?

  fewer trees means that less carbon dioxide is removed from the atmosphere by photosynthesis
• What is the effect of burning fossil fuels?

  carbon that was locked up in fossil fuels is released as carbon dioxide
• What is the effect of creating waste?

  more landfill sites and more waste from agriculture means more carbon dioxide and methane released by decomposition of waste
• What is the result of extra Carbon dioxide from human activity?

  climate change
• What is the effect in global temperature increasing?

  polar ice caps melting which causes a rise in sea levels, increased flooding and coastal erosion
• What is the effect of changes in rainfall patterns?

  some regions might get too much or too little water which may affect the ability to produce food
• What will happen to storms?

  frequency and severity of storms increase
• What will happen to wild species?

  changes in temperature and amount of water available in habitat could affect the distribution of wild species
• What is carbon footprint?

  measure of the amount of carbon and other greenhouses gases released over the full cycle of something
• How can you reduce carbon footprint?

  using renewable energy sources or nuclear energy instead of fossil fuels. using more efficient processes to conserve energy and cut waste, reduces methane emissions. Governments could tax companies based on the amount greenhouse gases they emit. Using technology to capture carbon dioxide and store it deep underground in rock cracks
• What could be the downside to reducing Carbon dioxide emissions?

  impact economic growth of countries specifically developing countries
• Why do some individuals not want to reduce carbon dioxide emissions?

  lack of education don't know why changes are necessary
• What do fossil fuels like crude oil and coal contain?

  hydrocarbons
• What happens to hydrocarbons during combustion?

  carbon and hydrogen in these compounds are oxidised so carbon dioxide and water vapour are released into the atmosphere
• What is complete combustion?

  when there is plenty of oxygen and all the fuel burns
• What is incomplete combustion?

  when there is not enough oxygen and some of the fuel doesn't burn
• What is the result of incomplete combustion?

  solid particles of soot and unburnt fuel are released and carbon dioxide and carbon monoxide produced
• What are solid particles of soot also called?

  particulates