Molybdenum , wolfram

The works by Volpin and Shur [160] as well as by Shilov [161] on molecular nitrogen fixation via complexing with transition metals indicates nitrogen readily reacting with low-valence organometallic compounds of titanium, chromium, molybdenum, wolfram and iron. 

Give the name and formula of one ore of each of the following metals chromium, manganese, molybdenum, wolfram, uranium. 

Mor] Mori, T., Aketa, K., Ono, H., Sugita, H., Effects of Molybdenum, Wolfram and Copper on Solubility of Graphite in Liquid Iron and the Method of Calculation for the Activity of Carbon in a Multicomponent Solution (in Japanese), Tetsu-to-Hagane (J. Iron Steel Inst. Jpn), 46, 1429-1439 (1960) (Thermodyn., Experimental, Calculation, 24)... 

Ekstrom T (1972) Formation of ternary phases of M05O14 and M017O47 structure in the molybdenum-wolfram-oxygen system. Mater Res Bull 7 19-26... 

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... 

Molybdenum and its uses. Molybdenite, molybdenum trioxide, ammonium molybdate. Wolfram (tungsten) and its uses. Scheelite, CaWO, and wolframite, (Fe,Mn)W04. Wolfram carbide. Uranium and its ores pitchblende, car-notite. Sodium diuranate, uranyl nitrate. Nuclear fission. 

This group of transition metals is exceptional in many respects. First, molybdenum and tungsten (synonym wolfram) are present in the Earth s crust and sea water in much higher amounts than their high atomic numbers would predict. Second, the trace elements of this group are mainly Mo and W of the second and third transition period, while Cr of the first period is a trace element only in rare cases. This makes W the trace element with the highest known atomic mass. 

Equilibrium data are not available for 83nstems containing NiS or NisS2 in combination with molybdenum sulfide, tungsten (wolfram) sulfide, or chromium sulfide. 

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

Von Ruprecht and Tondy in a letter to von Bom claimed to have obtained molybdenum, tungsten (mentioning Hjelm) and also metals from baryta, magnesia, and silica, by reducing the oxides with carbon at a high temperature, but their work was criticised by Klaproth. Raspe (1785) showed that the metals from wolfram and scheelite were the same (see Vol. II, p. 734). 

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