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The chemical elements can be broadly divided into metals, metalloids, and nonmetals according to their shared physical and chemical properties.All elemental metals have a shiny appearance (at least when freshly polished); are good conductors of heat and electricity; form alloys with other metallic elements; and have at least one basic oxide.
In the context of metals, an alloy is a substance having metallic properties which is composed of two or more elements. Often at least one of these is a metallic element; the term "alloy" is sometimes used more generally as in silicon–germanium alloys. An alloy may have a variable or fixed composition.
The periodic trends in properties of elements. In chemistry, periodic trends are specific patterns present in the periodic table that illustrate different aspects of certain elements when grouped by period and/or group. They were discovered by the Russian chemist Dmitri Mendeleev in 1863.
An example is the mineral eugenite (Ag 11 Hg 2) and related forms. [7] Silver nuggets, wires, and grains are relatively common, but there are also a large number of silver compound minerals owing to silver being more reactive than gold.
A material property is an intensive property of a material, i.e., a physical property or chemical property that does not depend on the amount of the material. These quantitative properties may be used as a metric by which the benefits of one material versus another can be compared, thereby aiding in materials selection.
Electronic article surveillance (such as passive ID tags) often uses metallic glasses because of these magnetic properties. Ti-based metallic glass, when made into thin pipes, have a high tensile strength of 2,100 MPa (300 ksi), elastic elongation of 2% and high corrosion resistance. [ 35 ]
Nickel(I) complexes are uncommon, but one example is the tetrahedral complex NiBr(PPh 3) 3. Many nickel(I) complexes have Ni–Ni bonding, such as the dark red diamagnetic K 4 [Ni 2 (CN) 6] prepared by reduction of K 2 [Ni 2 (CN) 6] with sodium amalgam. This compound is oxidized in water, liberating H 2. [44]
The structural chemistry of boron is dominated by its small atomic size, and relatively high ionization energy. With only three valence electrons per boron atom, simple covalent bonding cannot fulfil the octet rule. [250] Metallic bonding is the usual result among the heavier congenors of boron but this generally requires low ionization ...