Gallium

In the periodic table of chemical elements Gallium is in 3 main sub-group of 4 periods. Atomic number is 31. Gallium is a light metal. It is ductile and soft metal with silvery-white color and bluish tint. The name of the element gave Paul Lecoq de Efmilya Boisbaudran. He named this new element after his homeland - Gaul. 

The physical properties of gallium: 
Crystalline gallium has a number of polymorphs modifications. The thermodynamically stable is the only one. Other versions of this item are crystallized from the overchilled dispersed metal and are fragile. 
In the solid state at temperature of 20 ° C the density of Gallium is 5.904 g / cm ³. Liquid gallium has a density of 6.095 g / cm ³, at a temperature of 29,8 ° C. Thus, during solidification increases the amount of gallium. The boiling point of gallium is 2230 ° C, and melting temperature is 29,8°C. The basic gallium peculiarity is a wide temperature range (from 30 to 2230 ° C). In this case there is a low vapor pressure at a temperature of 1100-1200 ° C. 

In the solid and liquid state electrical resistivity of gallium is the same. Surface tension at temperature of 30°C in an atmosphere of hydrogen is 0.735 N/m. Natural gallium consists of two isotopes. 

The chemical properties of gallium: 
According to its chemical properties gallium is close to aluminum. The film which forms on its surface protects the metal form the oxidation.  
Gallium reacts with hot water and at reaction with superheated steam forms a compound of gallium hydroxide. Gallium perfectly reacts with mineral acids which release hydrogen and form salts even at temperature lower than the average room. Gallium does not react with carbon, hydrogen, nitrogen, bromine and silica. At high temperatures gallium can destroy a variety of materials, having a stronger melting effect for any metal. 

The usage of gallium: 
Gallium arsenide is wonderful and promising material used in semiconductor electronics. It is used for creation of light-emitting diodes and lasers of ultraviolet and blue range. Gallium is an expensive metal. 1ton price in 2005 was 1.2 million dollars. Gallium is also an excellent lubricant. There are various metallic glues with gallium basis.

Rolling types: 
Some types of rolled products of metal alloys contain gallium impurities: bars and wires, sheets, etc. 
Methods of gallium determination in the alloys are determined in accordance with State Standard: Gallium. Method of tin determination with State Standard 13637.5-93. Gallium. Method of selenium determination with State Standard 13637.6-93. Gallium. Method of phosphorus determination with State Standard 13637.9-93. Gallium. Method of tellurium determination with State Standard 13637.8-93. Gallium. Method of sulfur determination State Standard 13637.7-93. Gallium. Method of iron determination with State Standard 13637.4-93. 
State Standard 12697.13-90 method of gallium determination.