The evolution of the atmosphere Flashcards
How was the first formed earth like?
There was an atmosphere of helium and hydrogen.Early Earth was covered with active volcanoes.When the volcanoes erupted they gave off gases which formed the first atmosphere.
How long ago did the first atmosphere existed and what was the atmosphere made up of?
About 4000 million years ago.Made up of 74% water vapour (H2O),12% carbon dioxide,9% sulphur dioxide and 5% nitrogen.
What happened when the earth started to cool down(first atmosphere) and when did it occur?
The water vapour in the atmosphere condensed to form oceans.This then allowed the carbon dioxide in the atmosphere to begin dissolving in the water,reducing the amount in the air.This had happened about 3800 million years ago.
What and when did the first microscopic organisms developed in shallow seas?
About 3000 million years ago.These were simple organisms ,similar to algae.
How did microscopic organisms helped the atmosphere and how did they live?
They made their food from photosynthesis. They used the sunlight and carbon dioxide from the atmosphere and gave off oxygen.
What did volcanic activity release?
nitrogen which built up the atmosphere over-time,as well as water vapour and small amounts of methane and ammonia.
When the carbon dioxide was dissolved in the oceans,what happened next?
They went through a series of reactions to form carbonate precipitates that formed sediments on the seabed.
After when the green plants and algae evolved and absorbed some the carbon dioxide,what happened next?
Marine animals evolved.Their shells and skeletons contained carbonates from the oceans.
What happened to the carbons when the organism dies?
They became locked up in rocks and fossil fuels after the organisms died.
How do plants,plankton and marine animals reduce the amount of carbon dioxide in the atmosphere?
When they die,they fall to the seabed and get buried by layers of sediment.Over millions of years,they become compressed and form sedimentary rocks,oil and gas-trapping the carbon within them.
Can you give examples of fossil fuels?
coal,crude oil and natural gases.
How are crude oil and natural gas formed?
From the deposits of plankton .These fossil fuels for reservoirs under the seabed and when they get trapped in the rocks.
What is coal?
A sedimentary rock made from thick plant deposits.
what is Limestone?
A sedimentary rock.Mostly made of calcium carbonate deposits from the shells and skeletons of marine organisms.
What is the word equation for photosynthesis?
carbon dioxide+water=glucose+oxygen
