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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.
The nuclear industry enriches natural boron to nearly pure 10 B. The less-valuable by-product, depleted boron, is nearly pure 11 B. [149] Enriched boron or 10 B is used in both radiation shielding and is the primary nuclide used in neutron capture therapy of cancer.
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.
A table or chart of nuclides is a two-dimensional graph of isotopes of the elements, in which one axis represents the number of neutrons (symbol N) and the other represents the number of protons (atomic number, symbol Z) in the atomic nucleus. Each point plotted on the graph thus represents a nuclide of a known or hypothetical chemical element.
Boron's most common isotope is 11 B at 80.22%, which contains 5 protons and 6 neutrons. The other common isotope is 10 B at 19.78%, which contains 5 protons and 5 neutrons. [18] These are the only stable isotopes of boron; however other isotopes have been synthesised. Boron forms covalent bonds with other nonmetals and has oxidation states of 1 ...
Boron (1s 2 2s 2 2p 1) puts its new electron in a 2p orbital; carbon (1s 2 2s 2 2p 2) fills a second 2p orbital; and with nitrogen (1s 2 2s 2 2p 3) all three 2p orbitals become singly occupied. This is consistent with Hund's rule , which states that atoms usually prefer to singly occupy each orbital of the same type before filling them with the ...
(Note that the beryllium scale is inverted, so increases on this scale indicate lower beryllium-10 levels). Beryllium-10 has a half-life of 1.39 × 10 6 y, and decays by beta decay to stable boron-10 with a maximum energy of 556.2 keV. [7] [8] It is formed in the Earth's atmosphere mainly by cosmic ray spallation of nitrogen and oxygen.
This page uses the meta infobox {{Infobox isotopes (meta)}} for the element isotopes infobox.. This infobox contains the table of § Main isotopes, and the § Standard atomic weight.