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In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table ... Physical properties. As implied by the name, ...
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.
As is typical for early transition metals, zirconium and hafnium have only the group oxidation state of +4 as a major one, and are quite electropositive and have a less rich coordination chemistry. Due to the effects of the lanthanide contraction, they are very similar in properties. Titanium is somewhat distinct due to its smaller size: it has ...
Nickel was not formally named as an element until A. F. Cronstedt isolated the impure metal from "kupfernickel" (Old Nick's copper) in 1751. [11] In 1804, J. B. Richter determined the physical properties of nickel using a purer sample, describing the metal as ductile and strong with a high melting point.
Typical transition-metal properties are mostly absent from this group, as they are for the heavier elements of groups 4 and 5: there is only one typical oxidation state and the coordination chemistry is not very rich (though high coordination numbers are common due to the large size of the M 3+ ions).
Platinum is more ductile than gold, silver or copper, thus being the most ductile of pure metals, but it is less malleable than gold. [14] [15] Its physical characteristics and chemical stability make it useful for industrial applications. [16] Its resistance to wear and tarnish is well suited to use in fine jewellery.
Iron shows the characteristic chemical properties of the transition metals, namely the ability to form variable oxidation states differing by steps of one and a very large coordination and organometallic chemistry: indeed, it was the discovery of an iron compound, ferrocene, that revolutionalized the latter field in the 1950s. [59]
Aluminium combines characteristics of pre- and post-transition metals. Since it has few available electrons for metallic bonding, like its heavier group 13 congeners, it has the characteristic physical properties of a post-transition metal, with longer-than-expected interatomic distances. [25]