Boron

Boron, B, is a non-metallic element, found in Group IIIb of the periodic table.

Atomic Number : 5
Atomic Mass :

Discovery

Boron was isolated by Joseph Louis Gay-Lussac and J Thenard in 1808AD.

Occurrence

Boron exists as Borax in the alkaline lakes in California, USA.
Boron is also found as boric acid in the hot springs at Tuscany.

Preparation

Boron is prepared in the laboratory by the action of potassium on boron oxide.

	
	B2O3   +   3 K   ==>    KO    +    2 B

Properties

Boron is

a poor conductor of electricity at room temperature and a good conductor at high temperature,
in its crystalline form is a very hard solid with a quaesi-metallic sheen, and
in its amorphous form is a brown powder.

Reactions

Boron burns with a brilliant flame in oxygen to form boron trioxide.
Boron burns in air when heated to give a mixture of boron trioxide and Boron Nitride.
Boron is relatively inert and must be in a highly divided state to react with acids or alkalis.
Boron is oxidised by nitric acid to boric acid.
Boron reacts with fused sodium hydroxide to form sodium borate and hydrogen.

Uses

Boron is used

as a deoxidiser and flux in metallurgy,
in the manufacture of BoroSilicate Glass,
in the bearings of turbines the form of metallic borides where hardness and resistance to corrosion is required, and
in the nuclear industry as a moderator for neutrons.

Detection and Analysis

Boron is detected by converting the material under analysis to Borax by heating with concentrated nitric acid and then heating with concentrated sulphuric acid and ethanol to form ethyl borate, which burns with a green flame.

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