The radioactivity due to carbon-14 measured in a piece of a wooden casket from an ancient burial site is found to produce 20 counts per minute from a given sample, whereas the same amount of
Carbon from a piece of living wood produces 160 counts per minute. The half-life of carbon-14, a
Beta-minus emitter, is 5730 years. What would we calculate for the age of the artifact, assuming
That the activity for living wood has remained constant over time?

Question

Quizplus · Accepted Answer

The activity of the ancient wood is 1/8th that of the living wood, indicating that it has gone through three half-lives (since $2^3 = 8$). Three half-lives of carbon-14, at 5730 years each, gives an age of approximately 17,190 years, which rounds to the nearest option, 17,200 years.

The Radioactivity Due to Carbon-14 Measured in a Piece of a Wooden