Question

The organic molecules of living organisms have a measurably lower ratio of carbon-13/carbon-12, two stable isotopes of carbon. The ratio of carbon 13/carbon-12 is higher in non-organic molecules. What does this tell us about the rise in CO2 in the atmosphere over the last century? O Carbon dioxide molecules containg carbon-13 are heavier and sink to the ocean depths, making them less available to organisms. O The source of CO2 rise in the atmosphere is definitely due to the burning of the organic molecules in fossil fuels and not from release by volcanoes. O Oxygen atoms preferentially react with carbon-13, thereby enriching the atmosphere with carbon dioxide molecules containing carbon-13. O Carbon dioxide molecules with carbon-13 stay in the upper atmosphere and are less available to terrestrial plants and algae

Answer 1

Answer

Option b. The source of CO2 rise in the atmosphere is definitely due to burninh of the organic molecules in fossil fuels and not from release by volcanoes.

Explanation.

By measuring C13/C12 ratio in atmospheric CO2, we can conclude the source of CO2 being from organic molecules which contain higher amount of C12 than C13 isotope of carbon.