a black semi-metallic element found in some cleaning products

Properties

atomic number 5
atomic weight 10.811 amu

melting point 2079° C
boiling point 3927° C

In its crystalline form boron is the second hardest of all elements (after carbon).

Boron has a capacity to form stable covalently bonded molecular networks, making it similar to carbon.

Boron is a good electrical conductor at high temperatures but a poor conductor of electricity at room temperatures. Boron nitride also behaves like an electrical insulator, but conducts heat like a metal.

While some of the more exotic boron hydrogen compounds are toxic and require special care, elemental boron and common borates are considered safe.

Occurence

Boron does not occur in elemental form on Earth, but many boron compounds are found in sediments and sedimentary rock formations, and boric acid is sometimes found in volcanic spring waters. The most economically important sources of boron are rasorite (aka kernite) and tincal (aka borax ore), both of which are found in abundance in the Mojave Desert of California and in central and western Turkey.

Uses

Nearly all boron ore extracted from the Earth is destined for refinement into boric acid, which is used as a mild antiseptic and as a flame retardant, and borax, which is used in making fiberglass, as a cleansing fluid, a water softener, insecticide, herbicide, and disinfectant.

Boron compounds are also used to create metal alloys used in jet nozzles, rocket parts, tank armor, bullet-resistance vests, high-temperature equipment, and other applications requiring both hardness and heat resistance.

Neodymium-Iron-Boron (NIB) magnets are used in computers, cell phones, medical equipment, toys, motors, wind turbines and audio systems.

The isotope boron-10 is used as a control for nuclear reactors and as a shield for nuclear radiation, and in instruments used for detecting neutrons.

Boron compounds are also commonly used in fireworks to produce a very distinctive green color.

History

Boron was first isolated in 1808 by English chemist Sir Humphry Davy and, independently, by French chemists Joseph Louis Gay-Lussac and Louis Jacques Thenard.

The word "boron" was derived from the Arabic word buraq, as well as the Persian word burah, both of which are words for the mineral borax, a boron compound that has been used by man for hundreds of years.

Carbon
Sir Humphry Davy

Questions or comments about this page?