In other instances, gold nuggets are found in piles of residue in sites where mining operations once took place. Two gold nuggets are noted for being the largest masses of gold ever discovered. These are the "Welcome Stranger" and the "Hand of Faith". Their respective "largest" titles, however, carry further qualifications. mol-1 (third) Palladium is used in the following: 1. Catalytic converters; 2. Jewelry and watch making; 3. Dentistry and surgical instruments; 4. Aircraft spark plugs; 5. Electrical contacts; 6. Connector platings; 7. Manuscript illumination. Since the late 1930s, palladium has been utilized as a precious metal in jewelry. Today, however, they are highly regarded as investment and industrial commodities. Four of them, in fact - silver, gold, platinum, and palladium -, are minted into coins or cast into ingots and traded on commodity markets. All four are assigned the ISO 4217 currency code. Hence, the role of precious metals as investments, on top of their practical use, drives the demand for them. He named it after the asteroid Pallas, which was discovered on March 28 the year before. 3. Osmium - Smithson Tennant, an English chemist, discovered osmium in 1803 from the residues of platinum ores that were dissolved in nitro-hydrochloric acid. Osmium's characteristic of having a bad smell led to its naming as such, which was derived from the Greek word "osme", meaning "smell". Again, the X-ray fluorescence (XRF) method is the modern assay method widely used today for analyzing precious metals, including (besides silver, gold, and platinum) rhenium, ruthenium, iridium, and palladium. As a non-destructive assay method, XRF can identify various elements in a substance (in fact, even in powder and liquid ones) within a few minutes. Following is a list of some of the properties of rhenium: General: Chemical Symbol: Re Atomic Number: 75 Category (as an element): Transition Metal Group/ Period/ Block (in the Periodic Table): 7/ 6/ d Atomic Weight: 186.207 g.mol-1 Electron Configuration: [Xe] 4f14 5d5 6s2 Physical: Density (near room temperature): 21.02 g.
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