For example, (SiH 3) 3N is planar but (CH 3) 3N is tetrahedral. Silicon compounds are stereochemistry different from their carbon analogs. Multiple chemical bonding is also formed by using its vacant 3d- orbital and filled p-orbital with oxygen, nitrogen, or halogens atom.In most cases, it is attains by the formation of four covalent bonding with sp 3 hybridization.Therefore, attaining a noble gas configuration by losing four electrons is unfavorable. The sum of the four ionization energies is very high. At very high pressure, a denser distorted form may be produced, but the Si-Si bond distance remains practically unchanged. It crystallizes like a diamond with a Si-Si bond distance in the crystalline solid equal to 235 pm.Super pure silicon is used in the electronics industry as a semiconductor and obtained by zone refining. The compound SiCl 4 was purified by distillation and reduced by magnesium and zinc to produced pure silicon. The product is nearly 96 to 97 percent pure. The formation of SiC was prevented by using excess SiO 2. It is produced by reducing SiO 2 (sand) by high pure coke in an electric arc furnace Silica and silicates occur widely in the sand, clays, and various silicate minerals. It has a high affinity for oxygen forming the stable SiO 4 unit which combines with another to form a variety of silicates. Silicon is the second most abundant element after oxygen found 27.6 percent in the earth’s crust but it cannot be found free in nature. Therefore, silicon is a typical metalloid of group 14 (IVA) of the periodic table. It has four electrons in the outer quantum shell. The outer electronic configuration of the element is s 2p 2. The chemistry and the periodic table position of silicon are followed by its electronic configuration. The Latin word silex’ or silicis means flint Some important atomic and physical properties of silicon are summarized below the table, Silicon The trends of properties of group 14 elements may be largely understood from the valence shell electronic configuration. Due to the larger size and weaker bond energy, the meting point of the element is lower than that of carbon. It forms a face-centered diamond-type cubic crystal lattice. Silicon is the second most abundant element after oxygen in the earth’s crust.
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