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Rhodium is a hard, silvery, durable metal that has a high reflectance. Rhodium metal does not normally form an oxide, even when heated. [25] Oxygen is absorbed from the atmosphere only at the melting point of rhodium, but is released on solidification. [26] Rhodium has both a higher melting point and lower density than platinum.
World Book Encyclopedia, Exploring Earth. HyperPhysics, Georgia State University, Abundance of Elements in Earth's Crust. Eric Scerri, The Periodic Table, Its Story and Its Significance, Oxford University Press, 2007 "EarthRef.org Digital Archive (ERDA) -- Major Element Composition of the Core vs the Bulk Earth". earthref.org
Rhodium is a chemical element that is a rare, silvery-white, hard, and chemically inert transition metal and a member of the platinum group. It has the chemical symbol Rh and atomic number 45. It is composed of only one isotope, 103 Rh. Naturally occurring rhodium is found as the free metal, alloyed with similar metals, and never as a chemical ...
This list of chemical elements named after places includes elements named both directly and indirectly for places. 41 of the 118 chemical elements have names associated with, or specifically named for, places around the world or among astronomical objects.
The spectrum of copper minerals closely resembles that of silver, ranging from oxides of its multiple oxidation states through sulfides and silicates to halides and chlorates, iodates, nitrates and others. Natural alloys of copper (particularly with silver; the two metals can also be found in separate but co-mingled masses) are also found.
One of the largest bullion coins in the world was the 10,000-dollar Australian Gold Nugget coin minted in Australia, which consists of a full kilogram of 99.9% pure gold. In 2012, the Perth Mint produced a 1-tonne coin of 99.99% pure gold with a face value of $ 1 million AUD, making it the largest minted coin in the world with a gold value of ...
The abundance of the chemical elements is a measure of the occurrences of the chemical elements relative to all other elements in a given environment. Abundance is measured in one of three ways: by mass fraction (in commercial contexts often called weight fraction), by mole fraction (fraction of atoms by numerical count, or sometimes fraction of molecules in gases), or by volume fraction.
Naturally occurring platinum and platinum-rich alloys were known by pre-Columbian Americans for many years. [5] However, even though the metal was used by pre-Columbian peoples, the first European reference to platinum appears in 1557 in the writings of the Italian humanist Julius Caesar Scaliger (1484–1558) as a description of a mysterious metal found in Central American mines between ...