We know it is accurate because radiometric dating is based on the radioactive decay of unstable isotopes. For example, the element Uranium exists as one of several isotopes, some of which are unstable. When an unstable Uranium (U) isotope decays, it turns into an isotope of the element Lead (Pb).
How do we know radiometric dating works?
Radiometric Dating It is based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates. The best-known radiometric dating techniques include radiocarbon dating, potassium-argon dating, and uranium-lead dating.
What conditions are needed for an accurate radiometric date?
Accurate radiometric dating generally requires that the parent has a long enough half-life that it will be present in significant amounts at the time of measurement (except as described below under Dating with short-lived extinct radionuclides), the half-life of the parent is accurately known, and enough of the
How did life start on Earth?
We know that life on Earth is built around compounds that contain elements such as carbon, nitrogen, hydrogen and oxygen. The first traces of life recorded on Earth are thought to be as old as 4.2 billion years, indicating that life may have evolved within 200 million years after the first appearance of liquid water.