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Pure iridium is very difficult to pull into small diameter wires; at the same time, platinum has a low yield strength, which makes pure platinum wires bend too easily during insertion into nervous tissue. Additionally, platinum–iridium alloys containing oxides of both metals can be electro-deposited onto the surface of microelectrodes.
The only three verifications occurred in 1889, 1948, and 1989. For instance, the US owns five 90% platinum / 10% iridium (Pt‑10Ir) kilogram standards, two of which, K4 and K20, are from the original batch of 40 replicas distributed in 1884. [Note 4] The K20 prototype was designated as the primary national standard of mass for the US. Both of ...
Metallic iridium is found with platinum and other platinum group metals in alluvial deposits. [23] Naturally occurring iridium alloys include osmiridium and iridosmine, both of which are mixtures of iridium and osmium. It is recovered commercially as a by-product from nickel mining and processing. [20]
Iridium compounds are used as catalysts in the Cativa process for carbonylation of methanol to produce acetic acid. [92] [93] Iridium complexes are often active for asymmetric hydrogenation both by traditional hydrogenation. [94] and transfer hydrogenation. [95] This property is the basis of the industrial route to the chiral herbicide (S ...
Iridium-group platinum-group elements (IPGEs: Os, Ir, Ru). Subcategories. This category has the following 6 subcategories, out of 6 total. I. Iridium (2 C, 9 P) O.
Platinum is a chemical element; it has symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish platina, a diminutive of plata "silver". [7] [8] Platinum is a member of the platinum group of elements and group 10 of the periodic table of ...
(The Center Square) – A new Republican oversight report accuses former Congresswoman Liz Cheney of colluding with witnesses in the Jan. 6 Select Committee investigation that she oversaw. The ...
While lists of noble metals can differ, they tend to cluster around gold and the six platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum. In addition to this term's function as a compound noun, there are circumstances where noble is used as an adjective for the noun metal.