Chemistry of the Atmosphere
Where did the gases from the Earth's early atmosphere mainly come from?
Volcanoes
What was the early atmosphere thought to have contained?
No oxygen
Large amounts of carbon dioxide
Large amouts of water vapour
Small amounts of other gases (nitrogen and ammonia)
What is the modern atmosphere made up of? Give percentages.
Nitrogen 78%
Oxygen 21%
Carbon dioxide 0.04%
Noble gases and water vapour <1%
What causes small changes to happen in the atmosphere in the present day?
Volcanoes
Human activity such as burning fossil fuels, deforestation, farming
Increases in CO2 levels due to burning of fossil fuels leading to global warming
Explain the greenhouse effect.
Short wavelength radiation passes through the atmosphere to the Earth's surface where it radiates different wavelengths. The longer wavelengths are absorbed by greenhouse gases to produce temperature increases.