Boron compounds are used in silica-based glasses and ceramics to give them resistance to thermal shock. Boron polymers and ceramics play specialized roles as high-strength lightweight structural and refractory materials. The major industrial-scale uses of boron compounds are in sodium perborate bleaches, and the borax component of fiberglass insulation. Elemental boron is used as a dopant in the semiconductor industry. Several allotropes of boron exist: amorphous boron is a brown powder and crystalline boron is black, extremely hard, and a poor conductor at room temperature. Industrially, very pure boron is produced with difficulty, as boron tends to form refractory materials containing small amounts of carbon or other elements. These are mined industrially as evaporites, such as borax and kernite.Ĭhemically uncombined boron, which is classed as a metalloid, is not found naturally on Earth. Boron is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals. Because boron is produced entirely by cosmic ray spallation and not by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. Although only traces are required, it is an essential plant nutrient.įreebase Rate this definition: 0.0 / 0 votesīoron is a chemical element with symbol B and atomic number 5. Boron-containing organic antibiotics are known. Borates have low toxicity in mammals (similar to table salt) but are more toxic to arthropods and are occasionally used as insecticides. Consensus on it as essential for mammalian life is lacking. The intersection of boron with biology is very small. Natural boron is composed of two stable isotopes, one of which (boron-10) has a number of uses as a neutron-capturing agent. A few boron-containing organic pharmaceuticals are used or are in study. A small amount is used as a dopant in semiconductors, and reagent intermediates in the synthesis of organic fine chemicals. As sodium perborate, it is used as a bleach. Borosilicate glass is desired for its greater strength and thermal shock resistance than ordinary soda lime glass. The next leading use is in polymers and ceramics in high-strength, lightweight structural and heat-resistant materials. About half of all production consumed globally is an additive in fiberglass for insulation and structural materials. The primary use of the element itself is as boron filaments with applications similar to carbon fibers in some high-strength materials.īoron is primarily used in chemical compounds. Several allotropes exist: amorphous boron is a brown powder crystalline boron is silvery to black, extremely hard (about 9.5 on the Mohs scale), and a poor electrical conductor at room temperature. Industrially, the very pure element is produced with difficulty because of contamination by carbon or other elements that resist removal. The largest known deposits are in Turkey, the largest producer of boron minerals.Įlemental boron is a metalloid that is found in small amounts in meteoroids but chemically uncombined boron is not otherwise found naturally on Earth. These are mined industrially as evaporites, such as borax and kernite. It is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals. It constitutes about 0.001 percent by weight of Earth's crust. As the lightest element of the boron group it has three valence electrons for forming covalent bonds, resulting in many compounds such as boric acid, the mineral sodium borate, and the ultra-hard crystals of boron carbide and boron nitride.īoron is synthesized entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, so it is a low-abundance element in the Solar System and in the Earth's crust. In its crystalline form it is a brittle, dark, lustrous metalloid in its amorphous form it is a brown powder. Wikipedia Rate this definition: 0.0 / 0 votesīoron is a chemical element with the symbol B and atomic number 5.

Boron chemical element