Many things that are made of metals may, in fact, be made of mixtures of at least one metal with either other metals, or with non-metals. These mixtures are called alloys. Some common alloys are: The elemental metals have electrical conductivity values of from 6.9 × 10 3 S/cm for manganese to 6.3 × 10 5 S/cm for silver. In contrast, a semiconducting metalloid such as boron has an electrical conductivity 1.5 × 10 −6 S/cm. With one exception, metallic elements reduce their electrical conductivity when heated. Plutonium increases its electrical conductivity when heated in the temperature range of around −175 to +125°C. Metals can be doped with foreign molecules—organic, inorganic, biological, and polymers. This doping entails the metal with new properties that are induced by the guest molecules. Applications in catalysis, medicine, electrochemical cells, corrosion and more have been developed. [28] Recycling A pile of compacted steel scraps, ready for recycling 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.

The demand for precious metals is driven not only by their practical use, but also by their role as investments and a store of value. [16] Palladium and platinum, as of fall 2018, were valued at about three quarters the price of gold. Silver is substantially less expensive than these metals, but is often traditionally considered a precious metal in light of its role in coinage and jewelry. In some cases, for example in the presence of high energy gamma rays or in a very high temperature hydrogen rich environment, the subject nuclei may experience neutron loss or proton gain resulting in the production of (comparatively rare) neutron deficient isotopes. [21]In chemistry, metal is a word for a group of chemical elements that have certain properties. It is easy for the atoms of a metal to lose an electron and become positive ions, or cations. In this way, metals are not like the other two kinds of elements - the nonmetals and the metalloids. Most elements on the periodic table are metals. Most metals are solid at room temperature, but this does not have to be the case. Mercury is liquid. Alloys are mixtures, where at least one part of the mixture is a metal. Examples of metals are aluminium, copper, iron, tin, gold, lead, silver, titanium, uranium, and zinc. Well-known alloys include bronze and steel. Arsenic, zinc, antimony, and bismuth became known, although these were at first called semimetals or bastard metals on account of their immalleability. All four may have been used incidentally in earlier times without recognising their nature. Albertus Magnus is believed to have been the first to isolate arsenic from a compound in 1250, by heating soap together with arsenic trisulfide. Metallic zinc, which is brittle if impure, was isolated in India by 1300 AD. The first description of a procedure for isolating antimony is in the 1540 book De la pirotechnia by Vannoccio Biringuccio. Bismuth was described by Agricola in De Natura Fossilium (c. 1546); it had been confused in early times with tin and lead because of its resemblance to those elements. Hofmann S. 2002, On Beyond Uranium: Journey to the End of the Periodic Table, Taylor & Francis, London, ISBN 978-0-415-28495-0.

Metals up to the vicinity of iron (in the periodic table) are largely made via stellar nucleosynthesis. In this process, lighter elements from hydrogen to silicon undergo successive fusion reactions inside stars, releasing light and heat and forming heavier elements with higher atomic numbers. [17] By the end of World War II scientists had synthesized four post-uranium elements, all of which are radioactive (unstable) metals: neptunium (in 1940), plutonium (1940–41), and curium and americium (1944), representing elements 93 to 96. The first two of these were eventually found in nature as well. Curium and americium were by-products of the Manhattan project, which produced the world's first atomic bomb in 1945. The bomb was based on the nuclear fission of uranium, a metal first thought to have been discovered nearly 150 years earlier.

Heat and electricity can easily pass through a metal (it is conductive). A lump of metal can be beaten into a thin sheet (it is malleable) or can be pulled into thin wires (it is ductile). Metal is hard to pull apart (it has a high tensile strength) or smash (it has a high compressive strength). If you push on a long, thin piece of metal, it will bend, not break (it is elastic). Except for cesium, copper, and gold, metals have a neutral, silvery color. a b Siekierski, S.; Burgess, J. (2002). Concise Chemistry of the Elements. Horwood. pp.60–66. ISBN 978-1-898563-71-6. Von Welsbach, in 1906, proved that the old ytterbium also contained a new element (#71), which he named cassiopeium. Urbain proved this simultaneously, but his samples were very impure and only contained trace quantities of the new element. Despite this, his chosen name lutetium was adopted. 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.

About the Editors". Metals, Microbes, and Minerals – the Biogeochemical Side of Life. De Gruyter. 2021. pp.v–vi. doi: 10.1515/9783110589771-001. ISBN 9783110589771. S2CID 242357865. Tunay, Olcay; Kabdasli, Isik; Arslan-Alaton, Idil; Olmez-Hanci, Tugba (2010). Chemical Oxidation Applications for Industrial Wastewaters. IWA Publishing. ISBN 978-1-84339-307-8.The modern era in steelmaking began with the introduction of Henry Bessemer's Bessemer process in 1855, the raw material for which was pig iron. His method let him produce steel in large quantities cheaply, thus mild steel came to be used for most purposes for which wrought iron was formerly used. The Gilchrist-Thomas process (or basic Bessemer process) was an improvement to the Bessemer process, made by lining the converter with a basic material to remove phosphorus. Metals are usually inclined to form cations through electron loss. [6] Most will react with oxygen in the air to form oxides over various timescales ( potassium burns in seconds while iron rusts over years). Some others, like palladium, platinum, and gold, do not react with the atmosphere at all. The oxides of metals are generally basic, as opposed to those of nonmetals, which are acidic or neutral. Exceptions are largely oxides with very high oxidation states such as CrO 3, Mn 2O 7, and OsO 4, which have strictly acidic reactions. High-entropy alloys (HEAs) such as AlLiMgScTi are composed of equal or nearly equal quantities of five or more metals. Compared to conventional alloys with only one or two base metals, HEAs have considerably better strength-to-weight ratios, higher tensile strength, and greater resistance to fracturing, corrosion, and oxidation. Although HEAs were described as early as 1981, significant interest did not develop until the 2010s; they continue to be the focus of research in materials science and engineering because of their potential for desirable properties. Main article: Alloy Samples of babbitt metal, an alloy of tin, antimony, and copper, used in bearings to reduce friction 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]