Scientists use radiometric dating to determine the absolute age of a rock. Why is radiometric dating useful for this task?

Question

A.
Radioactive isotopes have brief half-lives, some less than a minute.

B.
A rock’s supply of radioactive isotopes stays constant over time.

C.
Radioactive isotopes decay at a constant rate.

D.
Radioactive isotopes readily form bonds with common, stable elements.

Answer 1

The correct answer is:

C. Radioactive isotopes decay at a constant rate.

Radiometric dating relies on the principle that radioactive isotopes decay at a predictable and constant rate, known as their half-life. This allows scientists to measure the amount of a radioactive isotope remaining in a rock or mineral and calculate how much time has passed since the rock formed, thus determining its absolute age.