It was identified from the residue of platinum ore which was dissolved in nitro-hydrochloric acid (also known as aqua regia). Platinum ores are still the main sources today of iridium. The precious metal is likewise obtained as a by-product of mining nickel. Below are some of the properties of iridium. This find made rhenium the last identified naturally occurring precious metal with stable isotopes. Actually, naturally occurring rhenium is composed of 2 stable isotopes and 26 unstable ones. 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. Of this group of metals, platinum is considered the most widely traded, as it is extensively used in the following: catalytic converters; dental alloys and other dentistry equipment; electrical conductors; resistive thermal devices, laboratory dishes and such other equipment capable of resisting chemical attack even in high temperature; and, of course, jewelry. One ounce coin (1.09 troy ounces in weight, 2.84 millimeters thick, and 32.77 millimeters in diameter). Each of these four coin varieties is 22K, containing 91.67% pure gold and 8.33% copper. This composition was meant to make the coins more durable and harder and thus resist dents and scratches, as, again, they were originally intended for circulation. Records have the following details about the Welcome Stranger: Gross weight: 3,523.5 troy ounces (241.61 pounds) Trimmed weight: 2,520 troy ounces (172.8 pounds) Net weight: 2,315.5 troy ounces (158.78 pounds) Measurement: 2 feet (0.61 meter) x 1.02 feet (0.31 meter) For their find, Deason and Oates were paid about 19,068 by the London Chartered Bank (located in the town of Dunolly in Victoria), where they took the nugget. Osmium - VIIIb/6; Os + 4 H2O -> OsO4 + 8 H+ + 8 e-; 0.838 V 6. Iridium - VIIIb/6; Ir -> Ir3+ + 3 e-; 1.156 V 7. Platinum - VIIIb/6; Pt -> Pt2+ + 2 e-; 1.18 V 8. Gold - Ib/6; Au -> Au3+ + 3 e-; 1.498 V The second item appearing after the name of the metal (the three items are separated by semi-colons) represents the metal's reaction in water.
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