Arrange the event from Earth's history to indicate the order in which they occured to produce the atmosphere we have today. Start from the earliest event. Events :
Photosynthesizing organisms develop.
The atmosphere becomes mostly water vapor and CO2.
Earth is a molten ball.
The atmosphere becomes mostly nitrogen.
The ancient oceans absorb the CO2 from the atmosphere.
Earth's surface hardens.
Oxygen and nitrogen make up 99 percent of the atmosphere.
Heavy rains fall for thousands of years from oceans.
Volcanoes spew gases from Earth's interior into the atmosphere.
Oxygen slowly builds up in the atmosphere.