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There are 2 parts per million of tantalum in the Earth's crust, making it the 51st most abundant element there. Soil contains on average 1 to 2 parts per billion of tantalum, and seawater contains 2 parts per trillion of tantalum. A typical human contains 2.9 parts per billion of tantalum. Tantalum is found in the minerals tantalite and ...
Tantalum electrolytic capacitors exploit the tendency of tantalum to form a protective oxide surface layer, using tantalum powder, pressed into a pellet shape, as one "plate" of the capacitor, the oxide as the dielectric, and an electrolytic solution or conductive solid as the other "plate".
The density implied by the adjective "heavy" has almost no biological consequences and pure metals are rarely the biologically active substance. [10] This characterization has been echoed by numerous reviews. [11] [12] [4] The most widely used toxicology textbook, Casarett and Doull’s toxicology [13] uses "toxic metal" not "heavy metals". [10]
Natural tantalum (73 Ta) consists of two stable isotopes: 181 Ta (99.988%) and 180m Ta (0.012%). There are also 35 known artificial radioisotopes, the longest-lived of which are 179 Ta with a half-life of 1.82 years, 182 Ta with a half-life of 114.43 days, 183 Ta with a half-life of 5.1 days, and 177 Ta with a half-life of 56.56 hours.
Tantalum pentoxide, also known as tantalum(V) oxide, is the inorganic compound with the formula Ta 2 O 5. It is a white solid that is insoluble in all solvents but is attacked by strong bases and hydrofluoric acid. Ta 2 O 5 is an inert material with a high refractive index and low absorption (i.e. colourless), which makes it useful for coatings ...
The mineral group tantalite [(Fe, Mn)Ta 2 O 6] is the primary source of the chemical element tantalum, a corrosion (heat and acid) resistant metal.It is chemically similar to columbite, and the two are often grouped together as a semi-singular mineral called coltan or "columbite-tantalite" in many mineral guides.
Treatment of tantalum pentachloride with hexamethylbenzene (C 6 Me 6), aluminium, and aluminium trichloride gives [M(η 6-C 6 Me 6)AlCl 4] 2. [7] Tantalum-alkyne complexes [8] catalyze cyclotrimerizations. [9] [10] Some tantalum-alkyne complexes are precursors to allylic alcohols. [11] Tantalacyclopropenes are invoked as intermediates.
Coltan is the colloquial name for the mineral columbite-tantalum ("col-tan"). In the early 21st century coltan mining is associated with human rights violations such as child labour, systematic exploitation of the population by governments or militant groups, exposure to toxic chemicals and other hazards as a result of lax environmental protection, and general safety laws and regulations. [1]