Which of the following methods is the most accurate way to measure the age of a relatively recent fossil?
A) ratio of carbon-14 to carbon-12
B) sequences of fossils in rock strata
C) ratio of plutonium-244 to uranium 240
D) ratio of uranium-238 to thorium-234

Question

Quizplus · Accepted Answer

The most accurate method for dating relatively recent fossils (up to about 50,000 years old) is by measuring the ratio of carbon-14 to carbon-12. Carbon-14 dating is based on the decay of carbon-14, a radioactive isotope of carbon, back into nitrogen-14. This method is widely used because all living organisms contain carbon, and a portion of that carbon is carbon-14. When the organism dies, it stops absorbing carbon-14, and the existing carbon-14 begins to decay at a known rate. By measuring the remaining carbon-14 to carbon-12 ratio, scientists can determine the age of the fossil.

Which of the Following Methods Is the Most Accurate Way