A researcher discovers a fossil of what appears to be one of the oldest-known multicellular organisms.The researcher could estimate the age of this fossil based on
A)the amount of uranium-238 in the fossil.
B)the amount of carbon-14 in the fossil.
C)the amount of uranium-238 in volcanic layers surrounding the fossil.
D)the amount of carbon-14 in volcanic layers surrounding the fossil.

Question

Quizplus · Accepted Answer

The age of the fossil can be estimated based on the amount of uranium-238 in volcanic layers surrounding the fossil. This is because uranium-238 decays into lead-206 at a known rate, so by measuring the ratio of uranium-238 to lead-206 in the volcanic layers surrounding the fossil, scientists can estimate the age of the rocks and therefore the fossil. Carbon-14 dating would not be appropriate for estimating the age of a fossil this old, as the half-life of carbon-14 is too short to be useful for dating samples more than about 50,000 years old.

A Researcher Discovers a Fossil of What Appears to Be