|
Papers > Technology > Precious metals
Featured Papers from Direct Essays |
|||
1. Italy
|
|||
This is a preview of a paper to view the full text you need to signup and login.
Precious metals |
|||
|
... Until recent times, it was considered essentially a monetary metal, and most of the bullion produced each year went into the vaults of government treasuries or central banks Among the elements in the periodic table, precious metals, specifically the platinum group metals, have unique properties. These include the metals resistance to chemical corrosion and oxidation, and their catalytic properties. Gold is one of the most precious metals in the world. ... When alloyed (chemically combined) with other base metals the melting temperature of the resulting alloy is changed. ... It is relatively heavy compared to most metals, such as silver (SG 10. ... · Is softer than most other metals. ... Fortunately, gold becomes harder when alloyed with other base metals. ... · Is able to bond with other base metals. ... 7%) of other base metals. ... The Avoirdupois weight system, where one pound equals 16 ounces, is used in the United States for most everything except precious metals. ... Gold plating or filled can be detected by testing a scratch in the item PLATINUM Platinum Group metals (Pt, Ir, Pd, Ru, Rh, Os) Group of precious metals (platinum, iridium, palladium, ruthenium, rhodium, and osmium) that share similar chemical and metallurgical properties. ... It is the heaviest of the precious metals, weighing almost twice as much as karat gold. Its strength ideally secures diamonds and other precious gems. ... As with all precious metals (gold, silver, etc. ... The dental applications have declined over the years with the development of alloys of base metals that are either equivalent to or in some cases better than gold. ... And of course there are applications ranging from electronics to medicine for this most interesting of metals. Iridium is the most inert of the precious metals. ... Some amounts of osmium are used to produce hardened alloys with other metals of the platinum group, for example, for fountain pen tips, and electrical contacts. ... Palladium is the least dense and lowest melting of the "platinum group" metals. ... Both ruthenium and rhodium are rarely used alone, because of their softness and are almost always alloyed with other metals. ... Like gold, there were previously large applications in dentistry, but with the rising cost of the metal as well as new technology involving base metals, this application is on the decline. ... While technically speaking, not a "platinum group metal", no discussion of these metals would be complete without saying at least something about silver. ... SILVER Silver has many special properties that make it a very useful and precious metal. ... Of all the metals, silver is the best conductor of heat and electricity known, in fact it has the highest electrical and thermal conductivity known for any material. ... Pure silver has the highest electrical and thermal conductivity of all metals, and possesses the lowest contact resistance. ... It is used in mirror production and may be deposited on glass or metals by chemical deposition, electrode position, or by evaporation. ... Silver coins of other countries have largely been replaced with coins made of other metals. |
|||
To link to this page, copy the following code to your site:
Paper Information |
|||||
Title: Precious metals
|
|||||
Signup & Login |
|||||
If you don't currently have a login then Signup here |
|||||
| Pre-Written Papers | |||||
|
|||||
| Custom Papers | |||||
|
|||||
Copyright 2003-2008 doingmyhomework.com. All rights reserved.