Evolution of the atmosphere Flashcards
1
Q
what does our atmosphere contain?
A
78% nitrogen
21% oxygen
and small amounts of water spur, noble gases and mainly carbon dioxide
2
Q
what happened in phase 1 of the atmosphere?
A
- earths surface - originally lotion
- too hot - any atmosphere boiled away
- cooled down - crust formed
- volcanoes still erupted - gave out lots of gases
- early atmosphere mainly CO2 + not really any oxygen
3
Q
what happened in phase 2 of the atmosphere?
A
- green plants happy in CO2 atmosphere
- early CO2 dissolved in oceans
- plants dies and were buried
- carbon & hydrocarbons became locked up in sedimentary rock - fossil fuels
- locked up carbon is released when buying fossil fuels
4
Q
what happened in phase 3 of the atmosphere?
A
- oxygen in atmosphere killed off some really organisms
- oxygen created the ozone layer
- virtually no CO2 left now
5
Q
what was the primordial soup theory?
A
- billions of years ago the atmosphere was made of nitrogen, hydrogen, methane & ammonia
- lightning - chemical reaction with gases - amino acids made
- amino acids collected in primordial soup
6
Q
what did Miller & Urey do in the 1950s?
A
sealed the gases in apparatus - heated - applied electrical charge for a week
7
Q
what did Miller & Urey found out?
A
amino acids were made in the experiment - not as many as on the earth
