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The properties of silicon may be used to modify alloys with metals other than iron. "Metallurgical grade" silicon is silicon of 95–99% purity. About 55% of the world consumption of metallurgical purity silicon goes for production of aluminium-silicon alloys ( silumin alloys) for aluminium part casts , mainly for use in the automotive industry .
Porous silicon (abbreviated as "PS" or "pSi") is a form of the chemical element silicon that has introduced nanopores in its microstructure, rendering a large surface to volume ratio in the order of 500 m 2 /cm 3.
Silicon is a chemical element, a hard dark-grey semiconducting metalloid, which in its crystalline form is used to make integrated circuits ("electronic chips") and solar cells. Silicones are compounds that contain silicon, carbon, hydrogen, oxygen, and perhaps other kinds of atoms as well, and have many very different physical and chemical ...
The most common is stable silicon-28, followed by stable silicon-29 and stable silicon-30. Silicon-32 is a radioactive isotope that occurs naturally as a result of radioactive decay of actinides, and via spallation in the upper atmosphere. Silicon-34 also occurs naturally as the result of radioactive decay of actinides. [18]
It melts at 1414 °C. Silicon is a semiconductor with an electrical conductivity of 10 −4 S•cm −1 [287] and a band gap of about 1.11 eV. [281] When it melts, silicon becomes a reasonable metal [288] with an electrical conductivity of 1.0–1.3 × 10 4 S•cm −1, similar to that of liquid mercury. [289]
Although silicon is a congener of carbon, having the same electron bonding configuration, silicon analogues of carbonaceous compounds generally exhibit different properties. The difference in total charge and mass between carbon with 6 protons and 6 neutrons, and silicon with 14 protons and 14 neutrons causes an added layer of electrons and ...
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]
Silicon dioxide is a relatively inert material (hence its widespread occurrence as a mineral). Silica is often used as inert containers for chemical reactions. At high temperatures, it is converted to silicon by reduction with carbon. Fluorine reacts with silicon dioxide to form SiF 4 and O 2 whereas the other halogen gases (Cl 2, Br 2, I 2 ...