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Gabriel, RA (1990). The Culture of War: Invention and Early Development. Westport CT: Greenwood Publishing Group. p.108. ISBN 978-0-313-26664-5. In humans, some metals are essential nutrients like iron, cobalt, and zinc. Some metals can be harmless such as ruthenium, silver, and indium. Some metals can be toxic in large amounts. Other metals such as cadmium, mercury, and lead, are very poisonous. Sources of metal poisoning include mining, tailings, industrial wastes, agricultural runoff, occupational exposure, paints and treated timber. In astronomy, a metal is any element other than hydrogen or helium. This is because these two elements (and sometimes lithium) are the only ones that form outside stars. In the sky, a spectrometer can see the signs of metals and show the astronomer the metals in a star.
Calcium is stored in a closed bottle but not under oil because it reacts with water less violently than potassium or sodium. Reactions of metals with dilute acid Paracelsus, a later German Renaissance writer, added the third principle of salt, carrying the nonvolatile and incombustible properties, in his tria prima doctrine. These theories retained the four classical elements as underlying the composition of sulfur, mercury, and salt.
Heavier metals are not usually formed this way since fusion reactions involving such nuclei would consume rather than release energy. [18] Rather, they are largely synthesised (from elements with a lower atomic number) by neutron capture, with the two main modes of this repetitive capture being the s-process and the r-process. In the s-process ("s" stands for "slow"), singular captures are separated by years or decades, allowing the less stable nuclei to beta decay, [19] while in the r-process ("rapid"), captures happen faster than nuclei can decay. Therefore, the s-process takes a more-or-less clear path: for example, stable cadmium-110 nuclei are successively bombarded by free neutrons inside a star until they form cadmium-115 nuclei which are unstable and decay to form indium-115 (which is nearly stable, with a half-life 30 000 times the age of the universe). These nuclei capture neutrons and form indium-116, which is unstable, and decays to form tin-116, and so on. [17] [20] [n 4] In contrast, there is no such path in the r-process. The s-process stops at bismuth due to the short half-lives of the next two elements, polonium and astatine, which decay to bismuth or lead. The r-process is so fast it can skip this zone of instability and go on to create heavier elements such as thorium and uranium. [22]
Metals are good conductors, making them valuable in electrical appliances and for carrying an electric current over a distance with little energy lost. Electrical power grids rely on metal cables to distribute electricity. Home electrical systems, for the most part, are wired with copper wire for its good conducting properties. Superalloys composed of combinations of Fe, Ni, Co, and Cr, and lesser amounts of W, Mo, Ta, Nb, Ti, and Al were developed shortly after World War II for use in high performance engines, operating at elevated temperatures (above 650°C (1,200°F)). They retain most of their strength under these conditions, for prolonged periods, and combine good low-temperature ductility with resistance to corrosion or oxidation. Superalloys can now be found in a wide range of applications including land, maritime, and aerospace turbines, and chemical and petroleum plants. Yonezawa, F. (2017). Physics of Metal-Nonmetal Transitions. Amsterdam: IOS Press. p.257. ISBN 978-1-61499-786-3. Sir Nevill Mott (1905–1996) wrote a letter to a fellow physicist, Prof. Peter P. Edwards, in which he notes... I've thought a lot about 'What is a metal?' and I think one can only answer the question at T = 0 (the absolute zero of temperature). There a metal conducts and a nonmetal doesn't. The discovery of bronze (an alloy of copper with arsenic or tin) enabled people to create metal objects which were harder and more durable than previously possible. Bronze tools, weapons, armor, and building materials such as decorative tiles were harder and more durable than their stone and copper (" Chalcolithic") predecessors. Initially, bronze was made of copper and arsenic (forming arsenic bronze) by smelting naturally or artificially mixed ores of copper and arsenic. [34] The earliest artifacts so far known come from the Iranian plateau in the fifth millennium BCE. [35] It was only later that tin was used, becoming the major non-copper ingredient of bronze in the late third millennium BCE. [36] Pure tin itself was first isolated in 1800 BCE by Chinese and Japanese metalworkers.Miss Armit: Yeah, because mercury's a great conductor of heat. So, when it gets hot the space between the particles expands and then this rises up the thermometer. A longtime goal of the alchemists was the transmutation of base metals into precious metals including such coinage metals as silver and gold. Most coins today are made of base metals with low intrinsic value; in the past, coins frequently derived their value primarily from their precious metal content. Chemically, the precious metals (like the noble metals) are less reactive than most elements, have high luster and high electrical conductivity. Historically, precious metals were important as currency, but are now regarded mainly as investment and industrial commodities. Gold, silver, platinum, and palladium each have an ISO 4217 currency code. The best-known precious metals are gold and silver. While both have industrial uses, they are better known for their uses in art, jewelry, and coinage. Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded. All metals discovered until 1809 had relatively high densities; their heaviness was regarded as a singularly distinguishing criterion. From 1809 onward, light metals such as sodium, potassium, and strontium were isolated. Their low densities challenged conventional wisdom as to the nature of metals. They behaved chemically as metals however, and were subsequently recognised as such. Reardon, Arthur C. (2011). Metallurgy for the non-metallurgist. Materials Park, Ohio: ASM International. pp.73–84. ISBN 978-1-61503-845-9. OCLC 780082219.
People first began making things from metal over 9000 years ago, when they discovered how to get copper from its ore. They then learned how to make a harder alloy, bronze, by adding tin to the copper. About 3000 years ago, they discovered iron. By adding small amounts of carbon to iron, they found that they could make a particularly useful alloy – steel.Georgius Agricola, De Re Metallica (1556) Tr. Herbert Clark Hoover & Lou Henry Hoover (1912); Footnote quoting De Natura Fossilium (1546), p. 180 The successful development of the atomic bomb at the end of World War II sparked further efforts to synthesize new elements, nearly all of which are, or are expected to be, metals, and all of which are radioactive. It was not until 1949 that element 97 (berkelium), next after element 96 (curium), was synthesized by firing alpha particles at an americium target. In 1952, element 100 (fermium) was found in the debris of the first hydrogen bomb explosion; hydrogen, a nonmetal, had been identified as an element nearly 200 years earlier. Since 1952, elements 101 (mendelevium) to 118 (oganesson) have been synthesized.
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