Where did the majority of the large amount of carbon dioxide (CO₂)from the second major atmosphere to form on the early Earth end up?
A) as nitrogen oxides and carbon, after chemical reactions with the majority component of the atmosphere, the nitrogen molecules
B) in plant life, where it was transformed into solid carbon and gaseous oxygen
C) dissolved in the oceans and, via the shells of living creatures, in the limestone of many mountain ranges
D) still in the atmosphere, though the quantity of nitrogen and oxygen has since risen to make these constituents the most abundant and relegate carbon dioxide to a minor constituent

Question

Quizplus · Accepted Answer

The majority of the carbon dioxide from the second major atmosphere ended up dissolved in the oceans and, through the shells of living creatures, in the limestone of many mountain ranges. This is supported by geological evidence of extensive limestone deposits and the fact that the oceans are currently the largest reservoir of carbon on Earth. Option A is incorrect because nitrogen oxides are not a significant sink for carbon dioxide and chemical reactions with nitrogen molecules would not result in carbon storage. Option B is incorrect because while photosynthesis does convert carbon dioxide into organic matter, the amount of carbon that can be stored in living plant life is relatively small compared to the total carbon dioxide in the atmosphere. Option D is incorrect because the amount of carbon dioxide in the atmosphere has decreased significantly over time, although it still plays a significant role in regulating Earth's climate.

Where Did the Majority of the Large Amount of Carbon