Discovered | Name | Characteristics | Found | Prepared | Uses

B is a metalloid, the lightest element of the Group IIIA (Group 13) elements. Other elements in this group are aluminum (Al), gallium (Ga), indium (In), and thallium (Tl).

Boron was discovered in 1808 by Sir Humphry Davy and independently by Gay-Lussac and Thénard. The name is derived from Arabic Bauraq, or Persian burah, meaning borax, its most important ore; the symbol B is derived from the name.

Boron exists as a dark brown to black amorphous powder and as an extremely hard, jet-black to silvery gray, brittle, lustrous, metal-like crystalline solid .

The chemistry of boron more closely resembles that of silicon than that of other elements of Group IIIA in the periodic table, illustrating a so-called "diagonal relationship." The crystalline form is much less reactive than the amorphous form, which ignites spontaneously in air at high temperatures.

Elemental boron has an energy band gap of 1.50 to 1.56 electron volts, which is higher than that of either silicon or germanium. It has interesting optical characteristics, transmitting portions of the infrared, and is a poor conductor of electricity at room temperature, but a good conductor at high temperature. Boron fibers, which have a very high tensile strength, can be added to plastics to make composite materials stronger than steel yet lighter than aluminum.

The element is not found free in nature, but occurs as boric acid usually in certain volcanic spring waters and as borates in borax and colemanite. Ulexite, another boron mineral, is interesting as it is nature's own version of fiber optics. By far the most important source of boron is the mineral kernite, found in the Mojave desert of California (see borax mining equipment ).

High purity crystalline boron may be prepared by the vapor phase reduction of boron trichloride or tribromide with hydrogen on electrically heated filaments.

2 BCl3(g) + 3 H2(g) 2 B(s) + 6 HCl(g)

Boron of 99.9999% purity has been produced and is available commercially. Impure, amorphous boron can be obtained by heating the trioxide with magnesium powder.

The most important compounds of boron are boric acid (H3BO3), which is used as a mild antiseptic, and borax [Na2B4O6(OH)2 3 H2O], which is used as a cleansing flux in welding, as a water softener in washing powders and detergents, and is a component of borosilicate glass .

Boron compounds are also extensively used to manufacture borosilicate glasses, which are found in labware and cookware because they do not crack upon rapid heating or cooling.

Boron compounds are used in production of enamels for covering steel of refrigerators, washing machines, and like products.

The isotope boron-10 is used in boron carbide control rods for nuclear reactors, as a shield for nuclear radiation, and in instruments used for detecting neutrons. Boron nitride has remarkable properties and can be used to make a material as hard as diamond. It is structurally similar to graphite, and, like graphite, it also has lubricating properties.

The boron hydrides are easily oxidized, with considerable energy liberation, and have been studied for use as rocket fuels.