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ConcepTest: Isotopic Dating with Parent to Daughter Ratios

ConcepTest questions by David McConnell , David Steer , Walter Borowski, Jeffrey Dick, Annabelle Foos, Jeffrey Knott, Alvin Konigsberg, Michelle Malone, Heidi McGrew, Kathie Owens, and Stephen Van Horn


The half-life of a radioactive isotope is 500 million years. Scientists testing a rock sample discover that the sample contains three times as many daughter isotopes as parent isotopes. What is the age of the rock?

a. 500 million years
b. 1,000 million years
c. 1,500 million years
d. 2,500 million years

Student Responses:

No data yet. The correct response is b.

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