Radiation application in radioactive dating
At least another 60 radionuclides are detectable in nature, either as daughters of primordial radionuclides or as radionuclides produced through natural production on Earth by cosmic radiation.More than 2400 radionuclides have half-lives less than 60 minutes.
(In theory, elements heavier than dysprosium exist only as radionuclides, but the half-life for some such elements, e.g. Unplanned exposure to radionuclides generally has a harmful effect on living organisms including humans, although low levels of exposure occur naturally without harm.(In theory, only 146 of them are stable, and the other 106 are believed to decay (alpha decay or beta decay or double beta decay or electron capture or double electron capture).) All chemical elements can exist as radionuclides.Even the lightest element, hydrogen, has a well-known radionuclide, tritium.There are about 730 radionuclides with half-lives longer than 60 minutes (see list of nuclides).Thirty-two of those are primordial radionuclides that were created before the earth was formed.