Topic 9-Chemistry Of The Atmosphere Flashcards
(47 cards)
How do we think the early atmosphere was formed
The earth’s surface was covered in volcanoes that erupted and released lots of gases
What was the early atmosphere made of
Mostly carbon dioxide and virtually no oxygen (like mars and venus today)
Volcanic activity released:
Volcanic activity also released nitrogen, which built up in the atmosphere over time, as well as water vapour and small amounts of methane and ammonia
How were oceans formed
When the water vapour in the atmosphere condensed it formed the oceans
How was carbon dioxide removed from the early atmosphere
Lots of carbon dioxide was removed from the early atmosphere as it dissolved in the oceans
What happened to the dissolved carbon dioxide
The dissolved carbon dioxide then went through a series of reactions to form carbonate precipitates that formed sediments on the sea bed
What evolved first and absorbed carbon dioxide
Green plants and algae evolved and absorbed some of the carbon dioxide for photosynthesis
What evolved after green plants and algae
Later marine animals evolved, their shells and skeletons contained carbonates from the oceans
Where did the carbon the organisms took in go
Some of the carbon these organisms took in from the atmosphere and oceans became locked up in rocks and fossil fuels after the organisms died
What happens when plants, plankton and marine animals die
They fall to the seabed and get buried by layers of sediment. Over millions of years, they become compressed to form sedimentary rocks, oil and gas-trapping the carbon within them and helping keep the carbon dioxide level in the atmosphere reduced
What is made from the process of plants, plankton and marine animals dying
Things like coal, crude oil and natural gas are made, these are known as fossil fuels
How are crude oil and natural gas formed
Crude oil and natural gas are formed from deposits of plankton. These fossil fuels form reservoirs under the seabed when they get trapped in rocks
What is coal
Coal is a sedimentary rock made from thick plant deposits
What is limestone
Limestone is a sedimentary rock. It’s mostly made of calcium carbonate deposits from the shells and skeletons of marine animals
As well as absorbing carbon dioxide what did green plants and algae produce
Green plants and algae also produced oxygen by photosynthesis
What are the approximate values that make up the atmosphere
80% nitrogen
20% oxygen
Small amounts of other gases (less than 1%)
Examples of greenhouse gases
- Carbon dioxide
- Methane
- Water vapour
What do greenhouse gases do
They act as an insulating layer in earth’s atmosphere which allows it to be warm enough to support life
All partickes absorb certain frequencies of radiation. What do greenhouse gases absorb
They don’t absorb the incoming short wavelength radiation from the sun but they do absorb the long wavelength radiation that gets reflected back off the earth
What is the greenhouse effect
The longwave radiation is thermal radiation so it results in warming of the surface of the earth
Deforestation
Fewer trees means less carbon dioxide is removed from the atmosphere via photosynthesis
Burning fossil fuels
Carbon that was locked up in these fuels is released as carbon dioxide
Agriculture
More farm animals produce more methane through their digestive processes
Creating waste
More landfill sites and more waste from agriculture means more carbon dioxide and methane released by decomposition of waste
