Studied by 0 people
Why is Evidence of the earths early atmosphere limited
Evidence is limited because of the time scale of 4.6 billion years and theories have changed/developed over time
how were gases introduced into the early atmosphere
There was intense volcanic activity that released gases that formed the early atmosphere
How was the atmosphere at the start of this period (refer to Mars and Venus)
At the start of this period, the atmosphere may have been like the atmospheres of Mars and Venus today: mainly CO2 with little or no O2 (g)
How was nitrogen introduced
-Volcanoes also produced nitrogen (N2 ) which gradually built up in the atmosphere
-there may have been small proportions of methane (CH4 ) and ammonia (NH3 )
How did oceans form
Water vapour condensed into oceans
How did CO2 decrease
CO2 dissolved in the water and carbonates were precipitated producing sediments, reducing the amount of CO2 in the atmosphere
Note 
Flashcard (25)