Boron

Boron, chemical element, symbol B; for physical constants see Periodic Table. Boron is not found free in nature, but its compounds have been known for thousands of years. The most important source of boron is the mineral kernite (sodium borate). A nonmetal, boron is prepared by the vapor phase reduction of boron trichloride with hydrogen on electrically heated filaments. It is similar to carbon in that it forms stable, covalently bonded molecular networks. Compounds of boron are used in the manufacture of fiberglass, bleach, laundry products, flame retardants, antiseptics, and borosilicate glasses. Boron-10 is used as a control in nuclear reactors. Filaments of boron are lightweight and strong and are used for aerospace structures.