INORGANIC CHEMISTRY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site gallium (Ga) Solid and liquid gallium. Credit: UCLA SPINLab A silvery-white metallic element of group III of the period table. Its chief sources are bauxite and some zinc ores. Gallium has such a low melting point that it will enter a molten if held in the hand and will then remain liquid when cooled down to 0°C. If, however, a globule of molten gallium is touch with a fragment of the solid metal, below its melting point, it will immediately solidify. It is used in lasers, transistor semiconductors, and high-temperature thermometers. Chemistry of gallium Gallium dissolves readily in hydrochloric acid and in potassium hydroxide with the evolution of hydrogen. It forms one oxide, Ga2O3, which is insoluble in water, but soluble in ammonia and potassium hydroxide. The chloride, nitrate, and sulfide are all very soluble in water; the sulfate combines with ammonia to form an alum. Discovery of gallium Gallium was discovered using spectroscopy by P. E. Lecoq de Boisbaudran in 1875 in a zinc blende found in the Pyrenees. However, its properties and salts were predicted before its discovery by Dmitri Mendeleyev based on his Periodic Law. Because it occupied a space immediately below aluminum according to that Law he suggested the name "eka-aluminium" for it. atomic number 31 relative atomic mass 69.723 electron configuration 1s22s22p63s23p64s23d104p1 atomic radius 130 pm oxidation states 3, 2, 1 density 5.91 g cm-3 melting point 29.76 °C (85.58 °F) boiling point 2,204 °C (3,999 °F) Related category    • INORGANIC CHEMISTRY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP