How do scientists find the ages of rocks?

Question

a. they measure the amount of the decay of particular unstable atoms in a rock
b. they measure rocks as they age; the bigger the rock of a particular type, the older they are
c. there is no completely accurate way to date rocks
d. all rocks on earth will be about the age of earth because rocks cannot be truly destroyed once created

Answer 1

The correct answer is:

a. they measure the amount of the decay of particular unstable atoms in a rock.

This process is known as radiometric dating, where scientists measure the abundance of radioactive isotopes and their stable decay products to determine the age of the rock.