radioisotopes with very long half-lives
1dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or …
2Radionuclide — A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this… …
3Isotope — This article is about the atomic variants of chemical elements. For the British jazz fusion band, see Isotope (band). Isotopes redirects here. For the minor league baseball team, see Albuquerque Isotopes. Isotopes are variants of atoms of a… …
4Chemical element — The periodic table of the chemical elements A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus.[1] Familiar examples of …
5Stable isotope — Graph of isotopes/nuclides by type of decay. Orange and blue nuclides are unstable, with the black squares between these regions representing stable nuclides. The unbroken line passing below many of the nuclides represents the theoretical… …
6Nuclear fission product — Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy… …
7Radioactive waste — 2007 ISO radioactivity danger logo, designed in part for long term radioactive waste depositories which might survive into a far future time in which all knowledge of the meaning of present common radiation danger symbols and signs has been lost… …
8Environmental radioactivity — is produced by radioactive materials in the human environment. While some radioisotopes, such as strontium 90 (90Sr) and technetium 99 (99Tc), are only found on Earth as a result of human activity, and some, like potassium 40 (40K), are only… …
9Caesium — xenon ← caesium → barium Rb ↑ Cs ↓ Fr …
10Radon — This article is about the chemical element. For other uses, see Radon (disambiguation). astatine ← radon → francium Xe ↑ Rn ↓ Uuo …
