Where did the gases that formed the Earths early atmosphere come from?

How much oxygen was present in the Earths early atmosphere?

How much Carbon Dioxide was present in the Earths early atmosphere?

Name 4 other gases present in the Earth’s early atmosphere.

How do scientists use rocks to work out the composition of the Earth’s early atmosphere?

How do scientists believe the oceans were formed?

Describe two ways that the carbon dioxide levels in the early atmosphere were reduced.

What mineral is limestone made from?

How did photosynthesis affect the composition of the atmosphere?

What is the current composition of the Earths atmosphere

State 3 ways humans changed the composition of the atmosphere.

What 2 main gases do volcanoes release in to the atmosphere

What effect does deforestation have on the amount of carbon dioxide in the atmosphere, explain