The Atmosphere Contains About 700

Multiple Choice

The atmosphere contains about 700. billion metric tons of carbon in the form of carbon dioxide. In the carbon cycle, about 200. billion metric tons of carbon (as carbon dioxide) enters the atmosphere each year. Assuming that 200. billion metric tons of carbon also leaves the atmosphere annually, how many years does the average carbon atom spend in the atmosphere in each cycle?

A) 0.29 years
B) 3.5 years
C) 500. years
D) 140,000 years
E) More information is needed in order to calculate the answer.