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Tin (50 Sn) is the element with the greatest number of stable isotopes (ten; three of them are potentially radioactive but have not been observed to decay). This is probably related to the fact that 50 is a "magic number" of protons.
Hydrogen (1 H) has three naturally occurring isotopes: 1 H, 2 H, and 3 H. 1 H and 2 H are stable, while 3 H has a half-life of 12.32(2) years. [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.
The other six isotopes forming 82.7% of natural tin have capture cross sections of 0.3 barns or less, making them effectively transparent to neutrons. [30] Tin has 31 unstable isotopes, ranging in mass number from 99 to 139. The unstable tin isotopes have half-lives of less than a year except for tin-126, which has a half-life of
The separation of hydrogen and deuterium is unusual because it is based on chemical rather than physical properties, for example in the Girdler sulfide process. Uranium isotopes have been separated in bulk by gas diffusion, gas centrifugation, laser ionization separation, and (in the Manhattan Project ) by a type of production mass spectrometry .
Since a nucleus with an odd number of protons is relatively less stable, odd-numbered elements tend to have fewer stable isotopes. Of the 26 "monoisotopic" elements that have only a single stable isotope, all but one have an odd atomic number—the single exception being beryllium. In addition, no odd-numbered element has more than two stable ...
Fusion forces together atoms of very light, stable elements like isotopes of hydrogen, creating slightly heavier elements like helium and producing as much as four times as much energy, per unit ...
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.
Of the 94 natural elements, eighty have a stable isotope and one more has an almost-stable isotope (with a half-life of 2.01×10 19 years, over a billion times the age of the universe). [15] [b] Two more, thorium and uranium, have isotopes undergoing radioactive decay with a half-life comparable to the age of the Earth.