The age of rocks is determined by radiometric dating, which looks at the proportion of two different isotopes in a sample. Radioactive isotopes break down in a predictable amount of time, enabling geologists to determine the age of a sample using equipment like this thermal ionization mass spectrometer.

## How does radiometric dating affect the way Earths age is determined?

Many chemical elements in rock exist in a number of slightly different forms, known as isotopes. By measuring the ratio of lead to uranium in a rock sample, its age can be determined. Using this technique, called radiometric dating, scientists are able to see back in time.

## What age is determined by radiometric dating?

For young organic materials, the carbon-14 (radiocarbon) method is used. The effective dating range of the carbon-14 method is between 100 and 50,000 years .Radiometric Age Dating.Original elementUranium-238Decay productLead-206Half-life (years)4.5 billionDated materialsZircon5 more columnsâ€˘3 Oct 2018