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No odd-neutron-number isotope is the most naturally abundant isotope in its element, except for beryllium-9 (which is the only stable beryllium isotope), nitrogen-14, and platinum-195. No stable nuclides have a neutron number of 19, 21, 35, 39, 45, 61, 89, 115, 123, or ≥ 127.
The next group is the primordial radioactive nuclides. These have been measured to be radioactive, or decay products have been identified in natural samples (tellurium-128, barium-130). There are 35 of these (see these nuclides), of which 25 have half-lives longer than 10 13 years. With most of these 25, decay is difficult to observe and for ...
Antimony is a chemical element; it has symbol Sb (from Latin stibium) and atomic number 51. A lustrous grey metal or metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb 2 S 3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl. [8]
The most common nuclide of the common chemical element lead, 208 Pb, has 82 protons and 126 neutrons, for example. [10] The table of nuclides comprises all the known nuclides. Even though it is not a chemical element, the neutron is included in this table. [11] Nuclear fission caused by absorption of a neutron by uranium-235.
Isotope half-lives. The darker more stable isotope region departs from the line of protons (Z) = neutrons (N), as the element number Z becomes larger. Isotopes are nuclides with the same number of protons but differing numbers of neutrons; that is, they have the same atomic number and are therefore the same chemical element. Isotopes neighbor ...
125 lead-193m2: 135 lead-198m2: 137 lead-196m3: 140 lead-190m1: 150 thallium-198m2: ... List of elements by stability of isotopes; List of nuclides; Orders of ...
The superactinides from unbipentium (element 125) to unbiennium (element 129) are predicted to exhibit a +6 oxidation state and form hexafluorides, though 125F 6 and 126F 6 are predicted to be relatively weakly bound. [84] The bond dissociation energies are expected to greatly increase at element 127 and even more so at element 129. This ...
All other isotopes have half-lives less than 4 days, most less than an hour. There are also many isomers , the longest-lived of which is 120m1 Sb with half-life 5.76 days. Except for beryllium , antimony is the lightest element observed to have isotopes capable of alpha decay ; 104 Sb is seen to undergo this mode of decay.