Geologic Time. There are several common radioactive isotopes that are used for dating rocks, artifacts and fossils. A method for determining the age of an object based on the concentration of a particular radioactive isotope contained within it. It is important that the radioactive isotope be contained within the sample being dated. Membrane Transport 5. Isotopes decay at a constant rate known as the half-life.
Dating Fossils – How Are Fossils Dated?
The specimens must contain a very long-lived radioisotope of known half-life time taken for one half of its nuclei to decaywhich, with a measurement of the ratio of radioisotope to a stable isotope usually the decay productgives the age. Try Study. Physical Geology: He eventually designed a device that used Geiger counters which measure radiation to accurately measure the amount of carbon left in an organic substance.