Topic 4 The Evolution Of The Atmosohere

Question 1

What happened in phase 1 of the earths atmosphere

Answer 1

Surface was covered in volcanoes that erupted and released lots of gasses 

Question 2

What made up earths early atmosphere

Answer 2

Mostly carbon with virtually no oxygen

Question 3

What was earths early atmosphere similar to

Answer 3

Mars and Venus today

Question 4

What does volcanic activity release

Answer 4

Nitrogen which is built up in the atmosphere over time
as well as water vapour
and small amounts of methane and ammonia

Question 5

What happened in phase 2 of atmosphere

Answer 5

Water vapour in the atmosphere condense to form oceans
Carmen dioxide is removed from the atmosphere dissolved into the oceans for a series of reactions to form carbon precipitate form sediments on the seabed
Green plants and algae evolved and absorb some of the carbon dioxide so that they could carry out photosynthesis later marine animals evolved their shells and skeletons contain carbonate from the ocean
Some of the carbon organisms talk in can be locked up in rocks and fossil fuels after the organism died

Question 6

How is carbon trap when planks plankton and marine animals die

Answer 6

They fall to the sea bed and get buried by layers of sediment over millions of years they become compressed and form sedimentary rocks oil and gas trapping the carbon and helping to keep carbon levels in the atmosphere reduced

Question 7

What are made by this process

Answer 7

Fossil fuels
Fuel
crude oil and natural gas

Question 8

What is crude oil and natural gas formed from deposits of

Answer 8

Plankton that gets trapped in rocks

Question 9

What is Coal

Answer 9

Are sedimentary rock made from thick plant deposits

Question 10

What is limestone

Answer 10

Sedimentary rock mostly made up of calcium carbonate deposit from shells and skeletons of marine organisms

Question 11

Phase 3 of the atmosphere

Answer 11

As well absorbing carbon dioxide green plants and algae produce oxygen by photosynthesis
Is oxygen built up in the atmosphere overtime more complex life could evolve
Eventually about 200, million years ago the atmosphere reached a composition similar to what it is today

Question 12

Gases in today’s atmosphere

Answer 12

80% nitrogen
20% oxygen
and small amounts of other gases