Carbon-14(14C) Dating Assumes That the Carbon on the Earth Today

Multiple Choice

Carbon-14(14C) dating assumes that the carbon on the Earth today has the same radioactive content as it did centuries ago. If this is true, then the amount of 14C absorbed by a tree that grew several centuries ago should be the same as the amount of 14C absorbed by a similar tree today. A piece of ancient charcoal contains only 18% as much of the radioactive carbon as a piece of modern charcoal. How long ago was the tree burned to make the ancient charcoal? (The half-life of 14C is 5715 years.) Round your answer to the nearest integer.

A) 2,310 years
B) 33,123 years
C) 2,315 years
D) 14,139 years
E) 14,144 years