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 columns•3 Oct 2018