Radioactive dating isotopes
Geologists can determine the ages of rocks and fossils by analyzing the isotopes found in them.
Radiation from certain isotopes can be used to treat cancer and to kill bacteria that cause food to spoil.
Carbon dating is mainly used by archaeologists to date recent finds as the technique is only accurate for 50,000 to 60,000 years in the past.
To date fossils, or rather the rocks in or near where the fossils are found, we use radioactive isotopes which have a much greater half life.
Igneous intrusions found cutting through, or above or below the strata containing the fossil is used to narrow down its age. Elemental atoms all have the same number of protons (and therefore also electrons); but they might vary in the number of neutrons.
There are many other isotopes of various elements used for dating the strata in which fossils are found. Two of the most common include carbon dating to discover how old fossils and other historical organic (including carbon) artifacts are and uses of radioactive isotopes in medicine.Radioactive isotopes in medicine are used to help diagnose certain disease states and isolate regions in the body.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. Carbon 14 is used, mainly by archaeologists, to date bones and other formerly living matter but not normally fossils.
For carbon dating, the isotope used is Carbon-14, which has a half life of 5,700 years.