1.9) Chemistry Of The Atmosphere Flashcards
What is the % of nitrogen in our current atmosphere?
about four-fifths (approximately 80%) nitrogen
What is the % of oxygen in our current atmosphere?
about one-fifth (approximately 20%) oxygen
There are other gases, but not an exact percentile.
small proportions of various other gases, including carbon
dioxide, water vapour and noble gases.
Describe how the early atmosphere was formed?
One theory suggests that during the first billion years of the Earth’s
existence there was intense volcanic activity that released gases
that formed the early atmosphere and water vapour that condensed
to form the oceans.
MAIN THING TO MEMORISE
(Frequent volcanic eruptions released gases)
Name the main gases in the early atmosphere?
Carbon dioxide, methane, ammonia and water vapour
Explain how the levels of oxygen increased.
The evolution of plants caused carbon dioxide to be absorbed and changed into oxygen by photosynthesis, which is released
Explain how the levels of carbon dioxide decreased
Carbon dioxide is absorbed by plants for use in photosynthesis. It is dissolves into the oceans and becomes locked up into sedimentary rocks/fossil fuels
Explain how nitrogen levels increased.
Ammonia + Oxygen → Nitrogen + Water
Explain why nitrogen levels have remained constant in the atmosphere.
Nitrogen isn’t a very reactive gas
Name 3 greenhouse gases.
Carbon dioxide, methane and water vapour.
Describe how the greenhouse effect is caused.
1.Electromagnetic radiation from the Sun passes through the Earth’s atmosphere.
2.The Earth absorbs electromagnetic radiation with short wavelengths and so warms up. Heat is radiated from the Earth as longer wavelength infrared radiation.
3.Some of this infrared radiation is absorbed by greenhouse gases in the atmosphere.
4.The atmosphere warms up.
Define term global warming.
Gradual increase in the average temperature of the Earth
Define term carbon footprint.
The total amount of carbon dioxide produced to directly and indirectly by human activities (in tonnes of CO₂
Define term climate change.
Large-scale, long-term shift in the Earth’s weather patterns or average temperatures.
Explain how human activity causes global warming.
Increased levels of carbon dioxide in the atmosphere cause more heat radiation to be trapped and cause the average temperature of the Earth to increase.
