BORON:

Boron is metalloids of 13^th group and it does not occur in Free State. The major ores of boron are a small number of borate (boron oxide) minerals, including

PREPARATION OF BORON:

(1) From Borax: Boron may be obtained by treating borax with hot concentrated HCl, or H₂SO_4,  igniting the boric acid H₃BO₃ to give the oxide B₂O₃ and finally reduced with Na, K, Al, Mg.

Step-(1) conversion of borax into boron oxide:

Step-(2) conversion of Boron oxide into boron:

(2) From Colemanite:

Physical properties:

(1) It is a non-metal. Boron occurs in two different allotropic forms Amorphous and   Crystalline

(2) Amorphous boron has not been obtained in the pure state.

(3) Crystalline boron is a black powder, extremely hard with a metallic appearance but with very low electrical conductivity.

Chemical properties:

(1) Reaction with non oxy acids:

(2) Reaction with Oxy acids:

(3) Reaction with Oxy water:

(4) Reaction with Base:

(5) Reaction with Metals:

(6) Reaction with Non-metals

 (7) Reaction with Ammonia:

Structure of Borazine: