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Silicon. face-centered diamond-cubic (cF8) Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium ...
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] The many tiny pores in porous silicon give it an enormous internal surface area, up to 1,000 m 2 /cm 3. [155]
Its chemistry is largely covalent in nature, noting it can form salt-like carbides with highly electropositive metals. The common oxide of carbon (CO 2) is a medium-strength acidic oxide. Silicon has a blue-grey metallic lustre. Silicon is a metallic-looking relatively unreactive solid with a density of 2.3290 g/cm 3, and is hard (MH 6.5) and ...
e. In the context of the periodic table a nonmetal is a chemical element that mostly lacks distinctive metallic properties. They range from colorless gases like hydrogen to shiny crystals like iodine. Physically, they are usually lighter (less dense) than elements that form metals and are often poor conductors of heat and electricity.
Appearance. Silicon compounds are compounds containing the element silicon (Si). As a carbon group element, silicon often forms compounds in the +4 oxidation state, though many unusual compounds have been discovered that differ from expectations based on its valence electrons, including the silicides and some silanes.
Amorphous metallic glasses are generally most easily prepared if one of the components is a metalloid or "near metalloid" such as boron, carbon, silicon, phosphorus or germanium. [ 173 ] [ n 20 ] Aside from thin films deposited at very low temperatures, the first known metallic glass was an alloy of composition Au 75 Si 25 reported in 1960. [ 175 ]
Silicon carbide (SiC), also known as carborundum (/ ˌ k ɑːr b ə ˈ r ʌ n d əm /), is a hard chemical compound containing silicon and carbon. A wide bandgap semiconductor , it occurs in nature as the extremely rare mineral moissanite , but has been mass-produced as a powder and crystal since 1893 for use as an abrasive .
Silicon is considered a bioessential element and is one of the most abundant elements on Earth. [2][3] The silica cycle has significant overlap with the carbon cycle (see carbonate–silicate cycle) and plays an important role in the sequestration of carbon through continental weathering, biogenic export and burial as oozes on geologic timescales.