mol-1 Atomic: * Oxidation States: 6, 5, 4, 3, 2, 1, -1, -2 * Electronegativity: 2.28 (Pauling scale) * Atomic Radius: 139 picometre * Covalent Radius: 136 5 picometre * Van der Waals Radius: 175 picometre * Ionization Energies: 870 kJ.mol-1 (first), 1791 kJ.mol-1 (second) Platinum is known to occur as only three thousandth parts-per notation (0.003 ppm) in the Earth's crust. Largest Gold Nuggets Discovered: Welcome Stranger And Hand Of Faith Gold nuggets are naturally occurring large masses of native gold found in alluvial deposits. Often they are concentrated by watercourses and recovered by placer mining. In other instances, gold nuggets are found in piles of residue in sites where mining operations once took place. Entering in a Contract For Difference (CFD): Some of the noted financial services firms, especially those in the United Kingdom, provide Contract for Difference (CFD). In this silver investment vehicle, two parties (a "buyer" and a "seller") enter into a contract, in which the seller agrees to pay the buyer the difference between the current value of silver and its value at contract time. A third important factor that will qualify an element as a precious metal, as may be noted from the uses of gold and silver above, is that it should not be radioactive. Thus, the chemical elements actinium, polonium, and radium are not considered precious metals because they are highly radioactive. Compared to most other elements, precious metals are chemically less reactive, have higher melting points, and are more ductile - properties that make them ideal for many commercial and industrial applications. 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. General: Chemical Symbol: Rh Atomic Number: 45 Category (as an element): Transition Metal Group/ Period/ Block (in the Periodic Table): 9/ 5/ d Atomic Weight: 102.90550 g.mol-1 Electron Configuration: [Kr] 4d8 5s1 Physical: Density (near room temperature): 12.41 g.cm-3 Liquid Density (at melting point): 10.7 g.