Boron << BAWR ahn >> , a chemical element , is an extremely hard metalloid . It is quite evenly distributed in small amounts throughout Earth’s surface. The chief sources of boron and boron compounds are mineral deposits that result from the evaporation of lakes and other bodies of water. Major deposits of boron minerals are found in Kazakhstan , Turkey , the United States , and a strip of South America from Peru to Argentina .
Boron is essential to proper plant growth. It also has many industrial uses. Adding boron to steel increases its hardness and its strength at high temperatures. An isotope of boron called boron 10 is used in nuclear reactors because of its ability to absorb neutrons . The isotopes of an element have the same number of protons , but different numbers of neutrons, in their nucleus.
Compounds of boron and oxygen , such as borax and boric acid , are used in heat-resistant glass, detergents and soaps, enamels, and medicines. A compound of boron and nitrogen , called boron nitride or Borazon , is one of the hardest materials known and is used as an abrasive.
Boron ranges from brown to black. It has the chemical symbol B. Its atomic number (number of protons) is 5. Its relative atomic mass is 10.811. An element’s relative atomic mass equals its mass (amount of matter) divided by 1/12 of the mass of carbon 12, the most abundant isotope of carbon. Boron has a melting point of 2180 °C and a boiling point of 3650 °C. At 20 °C, it has a density of 2.34 grams per cubic centimeter. Chemists classify boron as a metalloid . For information on the position of boron on the periodic table, see the article Periodic table .
Boron was first isolated and identified as an element in 1808 by the French scientists Joseph Louis Gay-Lussac and Louis Jacques Thenard. It was also independently discovered by the British scientist Sir Humphry Davy .
