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The thermal conductivity of silicon is better than that of most metals. [citation needed] A sponge-like porous form of silicon (p-Si) is typically prepared by the electrochemical etching of silicon wafers in a hydrofluoric acid solution. [152] Flakes of p-Si sometimes appear red; [153] it has a band gap of 1.97–2.1 eV. [154]
Metallurgy derives from the Ancient Greek μεταλλουργός, metallourgós, "worker in metal", from μέταλλον, métallon, "mine, metal" + ἔργον, érgon, "work" The word was originally an alchemist's term for the extraction of metals from minerals, the ending -urgy signifying a process, especially manufacturing: it was discussed in this sense in the 1797 Encyclopædia ...
Nonmetals show more variability in their properties than do metals. [1] Metalloids are included here since they behave predominately as chemically weak nonmetals.. Physically, they nearly all exist as diatomic or monatomic gases, or polyatomic solids having more substantial (open-packed) forms and relatively small atomic radii, unlike metals, which are nearly all solid and close-packed, and ...
This line has been called the amphoteric line, [2] the metal-nonmetal line, [3] the metalloid line, [4] [5] the semimetal line, [6] or the staircase. [2] [n 1] While it has also been called the Zintl border [8] or the Zintl line [9] [10] these terms instead refer to a vertical line sometimes drawn between groups 13 and 14.
Like a metallic element it can, for example, form a solvated cation in aqueous solution; [143] it can substitute for alkali metals in compounds such as the chlorides (NaCl cf. HCl) and nitrates (KNO 3 cf. HNO 3), and in certain alkali metal complexes [144] [145] as a nonmetal. [146]
These definitions are equivalent to stating that metals conduct electricity at absolute zero, as suggested by Nevill Francis Mott, [2]: 257 and the equivalent definition at other temperatures is also commonly used as in textbooks such as Chemistry of the Non-Metals by Ralf Steudel [3] and work on metal–insulator transitions. [4] [5]
In metallurgy, non-ferrous metals are metals or alloys that do not contain iron (allotropes of iron, ferrite, and so on) in appreciable amounts.. Generally more costly than ferrous metals, non-ferrous metals are used because of desirable properties such as low weight (e.g. aluminium), higher conductivity (e.g. copper), [1] non-magnetic properties or resistance to corrosion (e.g. zinc). [2]
a solid solution mixes with others to form a new solution The phase diagram in the above diagram displays an alloy of two metals which forms a solid solution at all relative concentrations of the two species. In this case, the pure phase of each element is of the same crystal structure, and the similar properties of the two elements allow for ...