In comparison, the half-life of the radioactive uranium 238 isotope is 4.5 billion years, which makes it useful for dating extremely old materials.

What isotope is used to date the oldest rocks?

isotope carbon-14 The best-known radiometric dating method involves the isotope carbon-14, with a half life of 5,730 years. Every living organism takes in carbon during its lifetime.

Which method could be used to date the oldest rocks on Earth?

To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.