Search results
Results From The WOW.Com Content Network
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
The even-longer half-life of 2.2 × 10 24 years of tellurium-128 was measured by a unique method of detecting its radiogenic daughter xenon-128 and is the longest known experimentally measured half-life. [5] Another notable example is the only naturally occurring isotope of bismuth, bismuth-209, which has been predicted to be unstable with a ...
A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example, carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, whereas the isotope concept (grouping all atoms of each element) emphasizes chemical over nuclear.
Isotopes are atoms of the same element (that is, with the same number of protons in their nucleus), but having different numbers of neutrons. Thus, for example, there are three main isotopes of carbon. All carbon atoms have 6 protons, but they can have either 6, 7, or 8 neutrons.
[3] [nb 1] Heavier isotopes also exist; all are synthetic and have a half-life of less than 1 zeptosecond (10 −21 s). [4] [5] Of these, 5 H is the least stable, while 7 H is the most. Hydrogen is the only element whose isotopes have different names that remain in common use today: 2 H is deuterium [6] and 3 H is tritium. [7]
Carbon (6 C) has 14 known isotopes, from 8 C to 20 C as well as 22 C, of which 12 C and 13 C are stable.The longest-lived radioisotope is 14 C, with a half-life of 5.70(3) × 10 3 years. . This is also the only carbon radioisotope found in nature, as trace quantities are formed cosmogenically by the reactio
[5] [6] Synthetic elements now present on Earth are the product of atomic bombs or experiments that involve nuclear reactors or particle accelerators, via nuclear fusion or neutron absorption. [7] Atomic mass for natural elements is based on weighted average abundance of natural isotopes in Earth's crust and atmosphere. For synthetic elements ...
An example of a mass independent process is the fractionation of oxygen atoms in ozone. This is due to the kinetic isotope effect (KIE) and is caused by different isotope molecules reacting at different speeds. [1] An example of a mass dependent process is the fractionation of water as it transitions from the liquid to gas phase.