An archaeologist wishes to estimate the age of an organic artefact using radioactive…
CHEMISTRY · Multi-part · US High School · Chemistry · Atomic Structure & Nuclear · Atomic Structure & Nuclear
Problem
An archaeologist wishes to estimate the age of an organic artefact using radioactive methods.
(i) Define the term half-life of a radioactive isotope.
(ii) Explain qualitatively how comparison of the present activity of 14C in the artefact with the activity in living matter permits an estimate of its age.
(iii) Potassium-40 has a half-life of 1.25×109y whereas Carbon-14 has a half-life of 5.73×103y. Which of these isotopes is more suitable for dating (a) an Iron Age wooden tool believed to be 3000 years old, and (b) a volcanic rock believed to be 70 million years old? Give reason for each choice.