BORON

DISCOVERED

Discovery date : 1808

Discovered by : Louis-Josef Gay-Lussac

and Louis-Jacques Thénard in Paris, France,

and Humphry Davy in London, UK.

Origin of the name : The name is derived from the Arabic 'buraq', which was the name for borax.

Allotropes : α-rhombohedral B, β-rhombohedral B, γ-B, tetragonal boron.


~>BORON is a chemical element with symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is a low-abundance element in the Solar system and in the Earth crust.

FACT BOX
Group 13 Melting point 2077°C, 3771°F, 2350 K
Period 2 Boiling point 4000°C, 7232°F, 4273 K
Block p Density (g cm−3) 2.34
Atomic number 5 Relative atomic mass 10.81
State at 20°C Solid Key isotopes 11B
Electron configuration [He] 2s22p1 CAS number 7440-42-8
ChemSpider ID 4575371 ChemSpider is a free chemical structure database

ELEMENTS and PERIODIC TABLE HISTORY

For centuries the only source of borax, Na2B2O5(OH)4, was the crystallized deposits of Lake Yamdok Cho, in Tibet. It was used as a flux used by goldsmiths.

In 1808, Louis-Josef Gay-Lussac and Louis-Jacques Thénard working in Paris, and Sir Humphry Davy in London, independently extracted boron by heating borax with potassium metal. In fact, neither had produced the pure element which is almost impossible to obtain. A purer type of boron was isolated in 1892 by Henri Moissan. Eventually, E. Weintraub in the USA produced totally pure boron by sparking a mixture of boron chloride, BCl3 vapour, and hydrogen. The material so obtained boron was found to have very different properties to those previously reported.