Niobium columbium , tantalum, vanadium

he element columbium (niobium) was discovered in 1801 by the English chemist Charles Hatchett, who was bom in London in 1765. As a young man in his thirties he engaged actively in chemical research, and published in the Philosophical Transactions an analysis o lead molybdate from Carinthia and the results of some experiments on shell and bone (2), and in Nicholson s Journal an analysis of an earth from New South Wales called Sydneia, or Terra Australis (81). 

The discovery on which his fame rests was announced before the Royal Society on November 26, 1801, in a paper entitled Analysis of a Mineral from North America containing a Metal hitherto Unknown (3). This mineral, now known as columbite, is a black rock found in New England, and the specimen Hatchett analyzed had an interesting history. 

Governor John Winthrop the Younger (30, 46, 52) used to take great pleasure in examining minerals, and his manner of collecting them is best described in the quaint words o an early American poet  

John Winthrop the Younger, 1606-1676. First governor of Connecticut. Alchemist, manufacturing chemist, and physician. His grandson sent the columbite from which Charles Hatchett later isolated the metal columbium. 

From Waters A Sketch of the Life of John Winthrop the Younger  

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Vanadium, vanadinite, carnotite, KV(S04)2 12H20, VOg, VO+ +, V0O5, NH4VO3. Niobium (columbium), tantalum columbite, tantalite TaC. 

Properties at 298.15 K (unless otherwise specified) Titanium Zirconium Hafnium (Celtium) Vanadium Niobium (Columbium) Tantalum Molybdenum Tungsten (Wolfram)... 

The atoms of the vanadium group metals have five valence electrons. In vanadium (Z — 23) and niobium (columbium, Z = 41), these valence electrons lie beyond ra re-gas cores, whereas in tantalum (Z = 73), they lie beyond the xenon core which has been augmented by fourteen 4/ electrons. The +5 oxidation state is characteristic of this family for niobium and tantalum it is the only oxidation state of importance. Oxidation is often regarded as removal of five valence electrons, followed by coordination of the pentapositive ion (which cannot exist for appreciable time in chemical systems) to basic groups which are present (H2O, OH, Cl, etc.). Although such a description almost certainly has very little resemblance to the actual path of oxidation of these metals, it is clerically convenient and may be used if not taken literally. In the same way, the lower oxidation states of vanadium may be considered vanadium atoms with the two 4s electrons removed, and with additional removal of one or two 3d electrons. 

Moissan s electric furnace was a valuable incentive to research. With its aid he prepared many uncommon metals such as uranium, tungsten (wolfram), vanadium, chromium, manganese, titanium, molybdenum, columbium (niobium), tantalum, and thorium, much of this work being done at the Edison Works on Avenue Trudaine (24, 61). As a practical... 

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