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As a metalloid the chemistry of silicon is largely covalent in nature, noting it can form alloys with metals such as iron and copper. The common oxide of silicon (SiO 2) is weakly acidic. Germanium. Germanium is a shiny, mostly unreactive grey-white solid with a density of 5.323 g/cm 3 (about two-thirds that of iron), and is hard (MH 6.0) and ...
Small changes in positions and d-levels lead to a metal-insulator transition in vanadium dioxide. [43] There are many cases where an element or compound is metallic under certain circumstances, but a nonmetal in others. One example is metallic hydrogen which forms under very high pressures. [44]
Non-metallic inclusions that arise because of different reactions during metal production are called natural or indigenous. They include oxides, sulfides, nitrides and phosphides. Apart from natural inclusions there are also parts of slag, refractories, material of a casting mould (the material the metal contacts during production) in the metal ...
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.
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]
It is a metalloid or a nonmetal in the carbon group that is chemically similar to silicon. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature. Because it seldom appears in high concentration, germanium was found comparatively late in the discovery of the elements.
Although most metal oxides are crystalline solids, many non-metal oxides are molecules. Examples of molecular oxides are carbon dioxide and carbon monoxide. All simple oxides of nitrogen are molecular, e.g., NO, N 2 O, NO 2 and N 2 O 4. Phosphorus pentoxide is a more complex molecular oxide with a deceptive name, the real formula being P 4 O 10.
Praseodymium metal tarnishes slowly in air, forming a spalling green oxide layer like iron rust; a centimetre-sized sample of praseodymium metal corrodes completely in about a year. [16] It burns readily at 150 °C to form praseodymium(III,IV) oxide, a nonstoichiometric compound approximating to Pr 6 O 11: [17] 12 Pr + 11 O 2 → 2 Pr 6 O 11