It uses the decay of samarium to neodymium, which has a half-life of billion years. Potassium and are stable, but potassium is unstable, giving us the dating methods discussed above. Daughter The element or isotope which is produced by radioactive decay. Guillermo Gonzalez U. For most radioactive nuclides, the half-life depends solely on nuclear properties and is essentially a constant. In these cases, usually the half-life of interest in radiometric dating is the longest one in the chain, which is the rate-limiting factor in the ultimate transformation of the radioactive nuclide into its stable daughter.
Additionally, lavas of historically known ages have been correctly dated even using methods with long half-lives.
Scientists have linked crater density to age for locations on the moon using radiometric dating of samples from Apollo missions. This would make the Earth 4.