For nearly 70 years, archaeologists have been measuring carbon-14 levels to date sites and artifacts. Nothing good can last—and in the case of carbon-14, a radioactive isotope found in Earths atmosphere, thats great news for archaeologists. Over time, carbon-14 decays in predictable ways.

## Which radioactive isotope S would be most useful in dating the age of the Earth?

The best-known radiometric dating method involves the isotope carbon-14, with a half life of 5,730 years.

## Which radioactive isotope appears to be the most useful for dating archaeological remains?

Carbon-14 dating, also called radiocarbon dating, method of age determination that depends upon the decay to nitrogen of radiocarbon (carbon-14).