federal agency CDC reveal that exposure to platinum salts, on the short term, may cause nose, throat, and eye irritation. Long-term exposure to these compounds, on the other hand, may cause skin and respiratory allergies. Palladium: Palladium in bulk metallic form is completely inert. The same can't be said though of the metal in finely divided form, which can readily ignite in air. And of all these precious metal coins, the South African gold bullion coin Krugerrand is perhaps the most popular. In 1967, the South African Mint Company introduced the Krugerrand, with the intention of circulating it as currency. Its status as a legal tender was seen as the best way for marketing South African gold around the world. Here, it is clear that the currency value assigned by the government to a gold bullion coin has no meaning. Below is a list of some of the government-issued gold and silver bullion coins: 1. Australian Gold Nugget, Lunar Series I, and Lunar Series II 2. Austrian Philharmoniker 3. Canadian Maple Leaf 4. Palladium - William Hyde Wollaston, an English chemist and physicist, discovered palladium in 1803 in samples of platinum ore obtained from South America. 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. Nuggets that have very rich deep orange/yellow color are sure to have higher gold content than pale ones. Also, there is a system called "millesimal fineness" which is used to denote the purity of gold alloy (also of silver and platinum alloys) by parts per thousand of pure metal by mass in the alloy. mol-1 Electron Configuration: [Xe] 4f14 5d6 6s2 Physical: Density (near room temperature): 22.59 g.cm-3 Liquid Density (at melting point): 20 g.cm-3 Melting Point: 3033 C, 5491 F, 3306 K Boiling Point: 5012 C, 9054 F, 5285 K Heat of Fusion: 57.85 kJ.mol-1 Heat of Vaporization: 738 kJ.mol-1 Atomic: Oxidation States: 8, 7, 6, 5, 4, 3, 2, 1, 0, -1, -2 Electronegativity: 2.2 (Pauling scale) Atomic Radius: 135 picometre Covalent Radius: 144 4 picometre Ionization Energies: 840 kJ.