The Atmosphere

Question 1

What happens in phase 1 earth?

Answer 1

Surface was molten
No atmosphere
Eventually cooled
Volcanoes erupted this released gases eg carbon dioxide, Methane
Mostly CO2 little o2
Water vapour later condensed to make oceans

Question 2

What happened in phase 2 earth?

Answer 2

Lots of co2 dissolved in oceans
Nitrogen put in atmosphere by denitrifying bacteria.
Nitrogen not reactive
Lots of green plants as photosynthesis this removed carbon dioxide and produce oxygen.
Over time less co2 More o2

Question 3

What happened in phase 3 earth?

Answer 3

Build of oxygen killed early organisms that could handle Change.
Allowed more complex organisms to develop due to more oxygen
It also created the ozone layer which blocked rays from sun, and allow for more complex systems.
No co2 left

Question 4

How do you test for oxygen?

Answer 4

Glowing splint test