Giant+Covalent+Structures

Vote for JJG, On The VLE


 * There are only five Giant Covalent Structures,namely:Diamond,Graphite,Silicon,Silicon dioxide,Silicon Carbide
 * Interestingly,Diamond is the hardest while Graphite is the softest.
 * Giant covalent structures are held by strong covalent bonds as large amounts of energy is required to overcome the strong covalent bonds between atoms in the giant 3-D covalent structure.
 * They are non electrical conductors(except graphite and silicon) because there is no no mobile ions/electrons as all valence electrons are localised in the covalent bonds between atoms.
 * They are insoluble in all solvents because large amounts of energy is required to overcome the strong covalent bonds between atoms in the giant 3-D covalent structure.
 * They are very hard(except graphite) as large amounts of energy is required to over come the strong COVALENT BONDS between atoms in the giant 3-D covalent structure.
 * In DIAMOND,each carbon atom is covalently bonded to four other carbon atoms in a basic tetrahedral unit.This basic unit is repeated infinitely to form a giant 3-D structure.This explains why diamond is very hard.
 * [|.com.sg/imglanding?q=structure+of+diamond&hl=en&safe=off&gbv=2&tbm=isch&tbnid=QcX_Tf-ORToFPM:&imgrefurl=http://www.uwgb.edu/dutchs/Petrology/Diamond%252520Structure.HTM&imgurl=http://www.uwgb.edu/dutchs/Graphics-Geol/ROCKMIN/ATOM-STRUCT/Diamond3.gif&w=450&h=450&ei=CcbPTZ7RKIborQfthtzCCg&zoom=1&iact=rc&page=1&tbnh=165&tbnw=165&start=0&ndsp=18&ved=1t:429,r:0,s:0&biw=1280&bih=685]
 * In Graphite,the layers of hexagonal rings are attracted to one another by weak van der Waals forces.When force is applied,the layers of hexagonal rings can slide over each other.This makes graphite soft and slippery and thus can be used as a lubricant for machinery.
 * [[image:http://www.everyscience.com/Chemistry/Inorganic/Carbon/.images/graphite2.gif]][]