Properties

Impure Boron was prepared almost at the same time from several chemists in 1808. The French chemists Joseph-Louis Gay-Lussac (1778-1850) and Louis Jacques Thénard (1777-1857) prepared it through the reduction of boron trioxide (B₂O₃) with potassium. Sir Humphrey Davy in London prepared it through the electrolysis of boric acid. Davy called the new element first "Boracium". This name was shortened later to “Boron”. The chemical symbol "B" was suggested by J. J. Berzelius in 1814. The preparation of highly pure boron was administered first by the American chemist W. Weintraub in 1909 through the reduction of boron trioxide with hydrogen in the electric arc.

The 5 crystal modifications of pure boron are:
     · amorphous (brown powder),
     · a-rhombohedral (red, translucent),
     · b-rhombohedral (black-gray, shiny),
     · a-tetragonal (black),
     · b-tetragonal (red).

Important boron modifications including other atoms are:
     · boron carbide B₂₄C (tetragonal boron carbide),
     · boron carbide B₁₃C₂ (a-rhombohedral boron carbide),
     · hexagonal boron nitride (a-boron nitride),
     · cubic nitride (b-boron nitride).

Boron is very heat-resistant, has a small density and a very high melting and boiling temperature. The electrical conductivity is very low at a temperature of 20°C (room temperature), but it is increasing tremendously when temperatures rise. At a temperature of 600°C, the electrical conductivity is hundred times larger than at room temperature. Boron has the highest tensile strength of all known elements. Boron is translucent to infrared light. Further important properties of boron are shown in the table below: