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Simply double-click the downloaded file to install it. You can choose your language settings from within the program. This is a good article. Follow the link for more information. This article is semi-protected until November 9, 2021. This article is about the chemical element.
B content may be as low as 19. B is the remainder in such cases. Industrially, very pure boron is produced with difficulty because of refractory contamination by carbon or other elements. Boron is primarily used in chemical compounds. A few boron-containing organic pharmaceuticals are used or are in study.
Boron compounds play a strengthening role in the cell walls of all plants, making boron a necessary plant nutrient. There is no consensus on whether boron is an essential nutrient for mammals, including humans, although there is some evidence it supports bone health. Italy in the 13th century. In 1808 Davy observed that electric current sent through a solution of borates produced a brown precipitate on one of the electrodes.
Gay-Lussac and Thénard used iron to reduce boric acid at high temperatures. By oxidizing boron with air, they showed that boric acid is an oxidation product of boron. Pure boron was arguably first produced by the American chemist Ezekiel Weintraub in 1909. The production of boron compounds does not involve the formation of elemental boron, but exploits the convenient availability of borates. Elemental boron is rare and poorly studied because the pure material is extremely difficult to prepare. Most studies of “boron” involve samples that contain small amounts of carbon. The rate of oxidation of boron depends on the crystallinity, particle size, purity and temperature.
Boron atoms are pink, with bridging oxygens in red, and four hydroxyl hydrogens in white. The oxidation state of all borons is III. This mixture of boron coordination numbers and formal charges is characteristic of natural boron minerals. The trichloride in practice is usually made from the oxide. In the most familiar compounds, boron has the formal oxidation state III. These include oxides, sulfides, nitrides, and halides. The trihalides adopt a planar trigonal structure.
Boron trifluoride is used in the petrochemical industry as a catalyst. These minerals resemble silicates in some respect, although boron is often found not only in a tetrahedral coordination with oxygen, but also in a trigonal planar configuration. Unlike silicates, the boron minerals never contain boron with coordination number greater than four. These compounds do not occur in nature. Many of the boranes readily oxidise on contact with air, some violently. The larger boranes all consist of boron clusters that are polyhedral, some of which exist as isomers.
A large number of anionic boron hydrides are known, e. 1 as in active metal hydrides. The mean oxidation number for the borons is then simply the ratio of hydrogen to boron in the molecule. In these compounds the oxidation state of boron is often not a whole number. Consequently, graphite and h-BN have very different properties, although both are lubricants, as these planes slip past each other easily. However, h-BN is a relatively poor electrical and thermal conductor in the planar directions.
Although these are not found on Earth naturally, boron forms a variety of stable compounds with formal oxidation state less than three. Ball-and-stick model of superconductor magnesium diboride. 1 on each boron atom. Binary metal-boron compounds, the metal borides, contain boron in negative oxidation states. However, unlike hexagonal boron nitride, which lacks electrons in the plane of the covalent atoms, the delocalized electrons in magnesium diboride allow it to conduct electricity similar to isoelectronic graphite. Certain other metal borides find specialized applications as hard materials for cutting tools. From the structural perspective, the most distinctive chemical compounds of boron are the hydrides.