paper 2 Flashcards
(10 cards)
what used to be the biggest component of the atmosphere (4.7 billion years ago)
carbon dioxide - it was released by volcanoes
why did water vapour graudually decrease?
it was released by volcanoes - too hot to condense and as it cooled down it condensed to form ocean
why did CO2 begin to decrease
water condenses to form oceans in which CO2 dissolves.
Algae and plants start to photosynthesis.
C02 precipitates in the oceans as solid carbonates that form rocks
why does oxygen begin to increase?
released as a product of photosynthesis
what is the proportion of gas in the atmosphere now?
80% nitrogen, 20% oxygen
what do green house gases do
they allow shorter wavelength radiation to pass through to earth and then absorb longer wavelength radiation from the earth
what does carbon monoxide come from and what does it do?
incomplete combustion of fuels, colourless and odourless toxic gas
what do particulutes come from and what do they do
incomplete combustion of fuels - global dimming, respiratory problems - cancer maybe
what about sulfur dioxide
acid rain and respiratory problems - sulfur impurities in fuel reacting w oxygen in air
what about oxides of nitrogen
nitrogen from the air being heated near an engine and reacting with oxygen - acid rain and respiratory problems.
