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Sunday, April 1, 2012

GOLONGAN 13


Boron
  • amorphous boron is used in pyrotechnic flares (distinctive green colour), and rockets (as an igniter)
  • boric, or boracic, acid, is used as a mild antiseptic
  • borax, Na2B4O7.10H2O, is a cleansing flux in welding
  • borax, Na2B4O7.10H2O is a water softener in washing powders
  • boron compounds are used in production of enamels for covering steel of refrigerators, washing machines, etc.
  • boron compounds are extensively used in the manufacture of enamels and borosilicate glasses
  • boron compounds show promise in treating arthritis
  • 10B is used as a control for nuclear reactors, as a shield for nuclear radiation, and in instruments used for detecting neutrons
  • boron nitride is as hard as diamond. It behaves like an electrical insulator, but conducts heat like a metal. It also has lubricating properties similar to graphite
  • the hydrides are sometimes used as rocket fuels
  • boron filaments, a high-strength, lightweight material, are used for advanced aerospace structures, .
  • lightweight compounds used for aerospace structures
  • boron filaments used in fibre optics research
  • Boric Acid is also used in North America for the control of cockroaches, silverfish, ants, fleas, and other insects.
 
Aluminium
  • cans and foils
  • kitchen utensils
  • outside building decoration
  • industrial applications where a strong, light, easily constructed material is needed
  • although its electrical conductivity is only about 60% that of copper per area of cross section, it is used in electrical transmission lines because of its lightness and price
  • alloys are of vital importance in the construction of modern aircraft and rockets
  • aluminium, evaporated in a vacuum, forms a highly reflective coating for both visible light and radiant heat. These coatings soon form a thin layer of the protective oxide and do not deteriorate as do silver coatings. These coatings are used for telescope mirrors, decorative paper, packages, toys, and in many other uses
  • the oxide, alumina, occurs naturally as ruby, sapphire, corundum, and emery, and is used in glass making and refractories. Synthetic ruby and sapphire are used in the construction of lasers
 
Gallium
  • gallium wets glass or porcelain, and forms a brilliant mirror when it is painted on glass
  • used for doping semiconductors and producing solid-state devices such as transistors
  • gallium arsenide converts electricity into coherent light
  • alloying
  • 90 tons of gallium (2 or 3 years of world production) is used to detect solar neutrinos by the use of the reaction: nu + 71Ga > 71Ge + e-. The rate, although very low (less than 1 interaction per day in 30 tonnes of Ga) makes gallium unique for this purpose. Two experiments are running : - GALLEX using 30 tons in the Gran Sasso underground laboratory (Italy) and SAGE with 60 tons in the Baksan laboratory in Caucasus (Russia). [thanks Michel]
 
Indium
  • used in making bearing alloys, germanium transistors, rectifiers, thermistors, and photoconductors
  • it can be plated onto metal and evaporated onto glass, forming a mirror as good as those made with silver, but with more resistance to atmospheric corrosion
  • photocells
  • used to make low-melting alloys, alloyed with gallium
  • indium is used in solders
 
Thallium
  • the sulphate was widely used as a rodenticide and ant killer. It is odourless and tasteless, giving no warning of its presence
  • the electrical conductivity of thallium sulphide changes with exposure to infrared light, and so it is used in photocells
  • thallium bromide-iodide crystals are used as infrared detectors
  • used, with sulphur or selenium and arsenic, to produce low melting glasses which become fluid between 125 and 150°C
  • originally used in treating ringworm and other skin infections. Its use was limited because of the narrow margin between toxicity and therapeutic benefits
  • A mercury-thallium alloy, which forms a eutectic at 8.5% thallium, freezes at -60°C, some 20° below the freezing point of mercury
 
Ununtrium
  • Element 113 has no uses as only a very few atoms of this element have been identified.



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