Non-metallic, non-fusible element, found in borax, etc.
Nonmetallic element, symbol B, atomic number 5, relative atomic mass 10.811. In nature it is found only in compounds, as with sodium and oxygen in borax. It exists in two allotropic forms (see allotropy): brown amorphous powder and very hard, brilliant crystals. Its compounds are used in the preparation of boric acid, water softeners, soaps, enamels, glass, and pottery glazes. In alloys it is used to harden steel. Because it absorbs slow neutrons, it is used to make boron carbide control rods for nuclear reactors. It is a necessary trace element in the human diet. The element was named by Humphry Davy, who isolated it 1808, from borax + -on, as in carbon.
A trivalent metalloid element; occurs both in a hard black crystal and in the form of a yellow or brown powder; SYN. B, atomic number 5.
B · atomic number 5
Unincorporated community in California (USA).