Radioactive decay allows geologists and physicists to measure the age of ancient fossils, rocks and even the Earth.
This process is called radiometric or radioactive dating.
those that form during chemical reactions without breaking down).
The unstable or more commonly known radioactive isotopes break down by radioactive decay into other isotopes.
After one half-life has elapsed, one half of the atoms of the nuclide in question will have decayed into a "daughter" nuclide, or decay product.
In many cases, the daughter nuclide is radioactive, resulting in a decay chain.
The best estimate from this dating technique says the man lived between 33 BC. From the ratio, the time since the formation of the rock can be calculated.This chain eventually ends with the formation of a stable, nonradioactive daughter nuclide.Each step in such a chain is characterized by a distinct half-life.This decay process leads to a more balanced nucleus and when the number of protons and neutrons balance, the atom becomes stable.This radioactivity can be used for dating, since a radioactive 'parent' element decays into a stable 'daughter' element at a constant rate.Radiometric dating, often called radioactive dating, is a technique used to determine the age of materials such as rocks.It is based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.By establishing geological timescales, radiometric dating provides a significant source of information about the ages of fossils and rates of evolutionary change, and it is also used to date archaeological materials, including ancient artifacts.The different methods of radiometric dating are accurate over different timescales, and they are useful for different materials.The rate of decay (given the symbol λ) is the fraction of the 'parent' atoms that decay in unit time.For geological purposes, this is taken as one year.