The rate of radioactive decay of various isotopes provide a variety of different timebases for "clocks" that can be used for measuring the ages of samples ranging from as little as a few hundred years (e.g. carbon dating) to as long as billions of years (e.g. uranium-lead dating).
Archaeology
Radio metric dating.
Are constant
Radiometric dating is possible because the rates of decay of radioactive isotopes are constant and predictable over time. By measuring the amount of remaining parent and daughter isotopes in a sample, scientists can determine the age of the sample.
amount if living organism that is expected to radioactive isotope.
radiometric dating is base on the half life of the radioactive atoms
The method compares the amount of a naturally occurring radioactive isotope and its decay products, in samples. The method uses known decay rates.
Amount of certain radioactive isotope in an object is compared with a reference amount. this ratio can then be used amount.
If radioactive decay rates were not constant, the passage of time inferred from radiometric dating would be inaccurate. Changes in decay rates would affect the ratio of parent to daughter isotopes used in dating, leading to flawed age calculations. The fundamental assumption of radiometric dating is that decay rates remain constant over time.
Radiocarbon dating is an absolute, (it is used provides a calender year/s for a particular event), radiometric (it is based on the known decay rate of a radioactive isotope) dating method.
CARBON DATING The most common fossil dating techniques are radiometric dating techniques. Radiometric dating uses knowledge of the decay rates of unstable ( radioactive ) nuclei to determine, by comparison with the proportion of stable nuclei in a fossil sample, the date of the introduction of the radioactive material into the live organism, especially if the isotope was ingested while the organism was alive.
Radiometric measurement is based on the decay of certain elements, the rate of which is a known scientific fact.