Quartz giant molecular structure.?

Question

Silicon, which is in group IV , why cannot form a giant molecular structure itself like carbon, but with oxygen to form quartz?

Answer 1

Solid silicon IS a giant molecular structure, just like diamond. It is a semiconductor rather than an insulator, because the band gap between bonding (filled) and antibonding (empty) bands is smaller. Its practical use, however, derives from the ability to dope it with impurities, which make it much more conducting.

Quartz is as you say a giant molecular structure. This is because second row typical elements form single rather than double bonds. Two reasons offered for this (both could be true): the so-called single Si-O bond has some double bond character because O "lone pairs" overlap vacant d-orbitals on Si, and the larger size of Si works against the good side-on overlap required for the pi component of ordinary double bonds like the ones in CO2.

Answer 2

Quartz Molecular Structure

Answer 3

Very simple... key is in the name. Giant covalent structures are linked by covalent bonds throughout. To melt, these bonds have to break in order for the substance to become runny. Breaking actually molecular bonds requires a lot of energy [heat]. Molecular structures have molecules held together by weak intermolecular forces, so it is easy for heat to vibrate them apart. Examples carbon dioxide [molecular] and diamond [giant molecular]