Uranium–lead radiometric dating involves using uranium-235 or uranium-238 to date a substances absolute age. This scheme has been refined to the point that the error margin in dates of rocks can be as low as less than two million years in two-and-a-half billion years.
What is used in absolute age dating?
Radiometric dating Radiometric dating Most absolute dates for rocks are obtained with radiometric methods. These use radioactive minerals in rocks as geological clocks. The atoms of some chemical elements have different forms, called isotopes. These break down over time in a process scientists call radioactive decay.
What do isotopes do with absolute age?
The isotopes will decay into a stable isotope over time. Scientists can tell how old the rock was from looking at the radioactive isotopes half-life, which tells them how long it would take for there to be half the radioactive isotope and half the stable isotope.