If the 14C to 12C ratio present in a fossil is 25% of that in living organism,how many years have passed since this fossilized organism died?
A)1,432
B)2,865
C)5,730
D)11,460
E)17,190

Question

If the 14C to 12C ratio present in a fossil is 25% of that in living organism,how many years have passed since this fossilized organism died?  
A)1,432
B)2,865
C)5,730
D)11,460
E)17,190

Quizplus · Accepted Answer

The half-life of Carbon-14 is approximately 5,730 years. If the 14C to 12C ratio is 25% of that in a living organism, it means two half-lives have passed (since 100% -> 50% -> 25%). Therefore, 2 x 5,730 = 11,460 years have passed.

If the 14C to 12C Ratio Present in a Fossil