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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. [1]
Boron (5 B) naturally occurs as isotopes 10 B and 11 B, the latter of which makes up about 80% of natural boron. There are 13 radioisotopes that have been discovered, with mass numbers from 7 to 21, all with short half-lives, the longest being that of 8 B, with a half-life of only 771.9(9) ms and 12 B with a half-life of 20.20(2) ms.
For example, the medical sciences refer to the biological half-life of drugs and other chemicals in the human body. The converse of half-life (in exponential growth) is doubling time. The original term, half-life period, dating to Ernest Rutherford's discovery of the principle in 1907, was shortened to half-life in the early 1950s. [1]
The shortest-lived is 7 B, with a half-life of a mere 350±50 × 10 −24 s, being the boron isotope with the fewest neutrons and a half-life long enough to measure. Some radioisotopes have important roles in scientific research; a few are used in the production of goods for commercial use or, more rarely, as a component of finished products.
Boron has two naturally occurring and stable isotopes, 11 B (80.1%) and 10 B (19.9%). The mass difference results in a wide range of δ 11 B values, which are defined as a fractional difference between the 11 B and 10 B and traditionally expressed in parts per
Polonium in the body has a biological half-life of about 30 to 50 days. Caesium in the body has a biological half-life of about one to four months. Mercury (as methylmercury) in the body has a half-life of about 65 days. Lead in the blood has a half life of 28–36 days. [29] [30] Lead in bone has a biological half-life of about ten years.
Beryllium-10 (10 Be) is a radioactive isotope of beryllium.It is formed in the Earth's atmosphere mainly by cosmic ray spallation of nitrogen and oxygen. [3] [4] [5] Beryllium-10 has a half-life of 1.39 × 10 6 years, [6] [7] and decays by beta decay to stable boron-10 with a maximum energy of 556.2 keV.
Neutron radiation is a form of ionizing radiation that presents as free neutrons.Typical phenomena are nuclear fission or nuclear fusion causing the release of free neutrons, which then react with nuclei of other atoms to form new nuclides—which, in turn, may trigger further neutron radiation.