c9

• abundance


  amount of something
• composition


  constituent parts of a whole
• atmosphere


  layer of vapor around a planetary of another body
• formula for nitrogen


  N2
• abundance of nitrogen in the atmosphere

  78%
• formula for oxygen


  O2
• abundance of oxygen in the atmosphere

  21%
• formula for argon


  Ar
• abundance of argon in the atmosphere

  0.9%
• formula for carbon dioxide

  CO2
• abundance of carbon dioxide in the atmosphere

  0.037%
• positive test for oxygen

  a glowing splint will relight
• positive test for carbon dioxide

  limewater will turn cloudy in the presence of carbon dioxide
• formula for hydrogen


  H2
• abundance of hydrogen in the atmosphere

  0.14%
• positive test for hydrogen


  a lighted splint will 'pop
• what does ppm mean

  parts per million
• how do you calculate ppm from the % abundance

  % abundance x 10,000
• abundance of neon in the atmosphere

  0.00182
• why have levels of carbon dioxide changed over time

  they have increased due to pollution
• what was the atmosphere like in the 1st billion years

  very dry, intense volcanic activity
• what was there lots of in the 1st billion years of the atmosphere

  CO2, water vapour, nitrogen
• what was there little of in the 1st billion years of the atmosphere

  methane, amonia
• explain how green plants + other organisms have changed the composition of the earths atmosphere

  - plants respire carbon dioxide + breathe out oxygen: this means the carbon dioxide will decrease and oxygen will increase
• overtime have carbon dioxide levels increased or decreased and why

  decreased due to photosynthesis and the fact that it has dissolved into the oceans
• overtime have oxygen levels increased or decreased and why

  increased due to photosynthesis
• overtime have nitrogen levels increased or decreased and why


  stayed the same as it is an inert (unreactive) gas
• overtime have methane levels increased or decreased and why

  decreased due to oxidation
• overtime have ammonia levels increased or decreased and why

  decreased due to oxidation
• what is the greenhouse effect

  the process by which gases hold heat in the atmosphere, keeping the earth warm
• 1st step of the greenhouse effect

  sunlight reaches the earth (UV + infrared)
• 2nd step of the greenhouse effect

  some of the energy is reflected back into space
• 3rd step of the greenhouse effect

  some of the energy is absorbed + re-radiated as heat
• 4th step of the greenhouse effect

  most of the heat is absorbed by greenhouse gases + radiated in all directions, warming the earth
• what are the 4 greenhouse gases

  carbon dioxide (CO2), methane (CH4), water vapour (H2O), nitrous oxides (N2O)
• factors which affect the levels of solar energy received

  latitude, climate, weather patterns
• factors which affect the levels of solar energy released

  greenhouse gases, land uses, deforestation
• what is global warming

  it refers to the rise in global temperatures due mainly to the increasing concentrations of greenhouse gases in the atmosphere
• what is climate change

  it refers to the increasing changes in the measures of climate over a long period of time - including precipitation, temperature, and wind patterns.
• what is the global warming potential

  a relative measure of how much heat a greenhouse gas traps in the atmosphere