What is silicon atom ?

     

Silicon is a chemical element with the symbol Si and atomic number 14.  It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid and semiconductor.  It is a member of group 14 in the table, carbon is above it, and germanium, tin, and lead are below it.  It is relatively unreactive.  Because of its high chemical affinity for oxygen, it was not until 1823 that jons jakob berzelius was first able to prepare it and characterize it in pure form.  

     Its oxides form a family of anions known as silicates.  Its melting and boiling point of 1414︒c and 3265︒c respctively are the second-highst among all the metlaloids and nonmetals, being only surpassed by boron.  Silicon is the eighth most common element in the universe by mass, but very very rarely occurs as the pure element in the Earth's crust.  t is most widely distributed in space in cosmic dusts, planetoids, and planets as various forms of silicon dioxide or silicates.  

     Most silicon is used commercially without being separated, and often with little processing of the natural minerals.  Such use includes industrial construction with clays, silica sand, and stone.  Silicates are used in portland cement for mortar and stucco and mixed with silica sand and gravel to make concrete for walkways, foundations and roads.  They are also used in whiteware ceramics such as porcelain, and in traditional quartz-based soda-lime glass and many other specialty glasses.  Silicon compounds such as silicon carbide are used as abrasives and components of high-strength ceramics.  Silicon is the basis of the widely used synthetic polymers called silicones. 

     Silicon is an essential element in biology, although only traces are required by animals.  However, various sea sponges and microorganisma, such as diatoms and radiolaria, secrete skeletal structures made of silica.  Silica is deposited in many plant tissues.