Search results
Results from the WOW.Com Content Network
Radioactive isotope table "lists ALL radioactive nuclei with a half-life greater than 1000 years", incorporated in the list above. The NUBASE2020 evaluation of nuclear physics properties F.G. Kondev et al. 2021 Chinese Phys. C 45 030001. The PDF of this article lists the half-lives of all known radioactives nuclides.
Of the first 82 elements in the periodic table, 80 have isotopes considered to be stable. [1] The 83rd element, bismuth, was traditionally regarded as having the heaviest stable isotope, bismuth-209, but in 2003 researchers in Orsay, France, measured the half-life of 209 Bi to be 1.9 × 10 19 years.
Six isotopes of livermorium are known, with mass numbers of 288–293 inclusive; the longest-lived among them is livermorium-293 with a half-life of about 80 milliseconds. A seventh possible isotope with mass number 294 has been reported but not yet confirmed. In the periodic table, it is a p-block transactinide element.
The list then covers the ~700 radionuclides with half-lives longer than 1 hour, split into two tables, half-lives greater than one day and less than one day. Over 60 nuclides that have half-lives too short to be primordial can be detected in nature as a result of later production by natural processes, mostly in trace amounts.
Proton number Z, also named the atomic number, determines the position of an element in the periodic table. The approximately 3300 known nuclides [7] are commonly represented in a chart with Z and N for its axes and the half-life for radioactive decay indicated for each unstable nuclide (see figure). [8]
Moscovium is an extremely radioactive element: its most stable known isotope, moscovium-290, has a half-life of only 0.65 seconds. [9] In the periodic table, it is a p-block transactinide element. It is a member of the 7th period and is placed in group 15 as the heaviest pnictogen.
Hassium is a synthetic chemical element; it has symbol Hs and atomic number 108. It is highly radioactive: its most stable known isotopes have half-lives of about ten seconds. [a] One of its isotopes, 270 Hs, has magic numbers of protons and neutrons for deformed nuclei, giving it greater stability against spontaneous fission.
In this situation it is generally uncommon to talk about half-life in the first place, but sometimes people will describe the decay in terms of its "first half-life", "second half-life", etc., where the first half-life is defined as the time required for decay from the initial value to 50%, the second half-life is from 50% to 25%, and so on.