Chemistry of the Atmosphere Flashcards
Approx how long ago was the Earth formed?
4.6 billion years ago
What is one theory of how the atmosphere was produced and gases within it
intense volcanic activity released gases made early Eart atmosphere similar to that of Mars and Venus (mainly carbon dioxide with little oxygen).
Nitrogen gas would havealso been released form volcanoes.
Water Vapour in Earths early atmosphere would have condensed to create the seas and oceans. Carbon dioxide would have disolved into the water decreasing the level in the atmosphere
What are the percentages of gases in the atmosphere?
78% nitrogen
21% oxygen
other including 1% argon
How did the levels of oxygen increase?
2.7 billion years ago algae first produced oxygen
gradually oxygen increased as plants evolved
this was followed by animals as the levels of oxygen increased to a level that would sustain more complex life
What do plants produce in the process of photosyntheses
oxygen
What is the process of photsynthesis
6CO2 (carbon dioxide) + 6H2O (water)
Light\chlorophyll
C6H1206 (GLUCOSE) + 6O2 (OXYGEN)
How did the levels of Carbon Dioxide decrease?
CO2 disolves in water, as water vapour condensed and the seas formed the CO2 gas disoved producing carbonate compounds. This reduced CO2 in the atmosphere. Carbonate compounds were then precipitated: limestone is an example of sedimentary rock; it has the chemical name calcium carbonate
How did the levels of Carbon Dioxide decrease?
plants in the ocean absorbed CO2 for photosyntesis. the organisms from the food chains that the plants supported were turned into fossil fuels. fossil fuels are non renewable and consist of coal, crude oil and gas all of which contain carbon
How is coal formed
coal is a fossil fuel fromed from giant plants that lived hundreds of millions of years ago in swamp like forests. When these plants died the sank to the bottom of the swamp where dirt and water began to pile on top of them. Over time pressure and heat increased and the plant remains underwent chemical and physical changes. The oxygen was pushed out and all that remained was coal
Why do they think greenhouse gases have increased?
human activities such as farming cattle and farming rice release huge amounts of methane into the atmosphere.
burning fossil fuels in cars and power stations releases large amount of CO2.
DEFORESTATION - EXCESS co2 is not being absorbed by photsynthesis
Apart from human activities what is another theory for rising global temperatures
associated with cycles of climate change and natural factors
What should you consider on wether you should trust a piece of climate research?
Has it been carried out by a legitimate source\organisation
Is the source a general newspaper which may sensationalise
Has the research been done by an expert in that field and has the right qualifications
