Assessing the Reliability of Material Flow Analysis Results: The Cases of Rhenium, Gallium, and Germanium in the United States Economy.

See more Gallium products. Gallium (atomic symbol: Ga, atomic number: 31) is a Block P, Group 13, Period 4 element with an atomic weight of 69.723.The number of electrons in each of Gallium's shells is 2, 8, 18, 3 and its electron configuration is [Ar] 3d¹⁰ 4s² 4p¹. The gallium atom has a radius of 122.1 pm and a Van der Waals radius of 187 pm. Gallium was predicted by Dmitri Mendeleev in 1871. It was first discovered and isolated by Lecoq de Boisbaudran in 1875. In its elemental form, gallium has a silvery appearance. Gallium is one of three elements that occur naturally as a liquid at room temperature, the other two being mercury and cesium. Gallium does not exist as a free element in nature and is sourced commercially from bauxite and sphalerite. Currently, gallium is used in semiconductor devices for microelectronics and optics. The element name originates from the Latin word 'Gallia' referring to Gaul, the old name of France.

See more Germanium products. Germanium (atomic symbol: Ge, atomic number: 32) is a Block P, Group 14, Period 4 element with an atomic weight of 72.63. The number of electrons in each of germanium's shells is 2, 8, 18, 4 and its electron configuration is [Ar] 3d¹⁰ 4s² 4p². The germanium atom has a radius of 122.5 pm and a Van der Waals radius of 211 pm. Germanium was first discovered by Clemens Winkler in 1886. In its elemental form, germanium is a brittle grayish white semi-metallic element. Germanium is too reactive to be found naturally on Earth in its native state. It is commercially obtained from zinc ores and certain coals. It is also found in argyrodite and germanite. It is used extensively as a semiconductor in transitors, solar cells, and optical materials. Other applications include acting an alloying agent, as a phosphor in fluorescent lamps, and as a catalyst. The name Germanium originates from the Latin word "Germania" meaning "Germany."

See more Rhenium products. Rhenium (atomic symbol: Re, atomic number: 75) is a Block D, Group 7, Period 6 element with an atomic weight of 186.207. The number of electrons in each of rhenium's shells is 2, 8, 18, 32, 13, 2 and its electron configuration is [Xe] 4f¹⁴ 5d⁵ 6s². The rhenium atom has a radius of 137 pm and a Van der Waals radius of 217 pm. Rhenium was discovered and first isolated by Masataka Ogawa in 1908. In its elemental form, rhenium has a silvery-white appearance. Rhenium is the fourth densest element exceeded only by platinum, iridium, and osmium. Rhenium's high melting point is exceeded only by those of tungsten and carbon. Rhenium is found in small amounts in gadolinite and molybdenite. It is usually extracted from the flue dusts of molybdenum smelters. The name Rhenium originates from the Latin word 'Rhenus' meaning "Rhine" after the place of discovery.