Answer and Explanation: Silica, quartz, is a covalently bonded network solid. The bonds are covalent since the electronegativities of Si and O are 1.9 and… See full answer below.
Answer and Explanation: The solid of silicon dioxide (SiO2) ( S i O 2 ) is a covalent crystal where valence electrons are shared between the silicon…
Silica has a covalent bond and forms a network structure. Silicic acid, SiO2, has a crystalline form called quartz that is found in many types of rock and is the second most common mineral in the earth’s crust. This very hard mineral is usually colorless.
Silica is a network solid due to the strong intermolecular covalent bond. In carbon dioxide, the molecules are held together by a weak van der Walls force. Therefore they are molecular solids. So the correct answer is option C.
But is silica ionic or covalent? Silicon dioxide is a covalent compound, more like a “polar covalent compound” in which each silicon atom of a crystal is covalently bonded to four oxygen atoms and each oxygen is covalently bonded to two silicon atoms.
SiO2 does not exist as a molecule, but exists as a network of Si and O bonds, with Si bonded to four O atoms. SiO2 simply denotes its proportion in the overall structure. Si-O bonds are very polar, but there are four Si-O bonds that cancel the dipole, making the structure as a whole non-polar.
Silica is another name for the chemical compound of silicon and oxygen with the chemical formula SiO2 or silicon dioxide. There are many forms of silica.
Ice is a molecular crystal in which the constituent units are molecules and the forces between the particles are hydrogen bonds.
Molecular solids have low melting (Tm) and boiling points (Tb) compared to metallic (iron), ionic (sodium chloride), and covalent solids (diamond ). Examples of molecular solids with low melting and boiling temperatures are argon, water, naphthalene, nicotine and caffeine (see table below).
6: Carbon dioxide (CO2) consists of small, non-polar molecules and forms a molecular solid with a melting point of −78 °C.
Sodium chloride (NaCl) is an ionic solid with cations and anions (Na+ and Cl-). Therefore sodium chloride is an example of an ionic crystal.
The molecular SiO2 has a linear structure like CO2 . SiO2 forms three-dimensional network solids in which each silicon atom is covalently tetrahedrally bonded to 4 oxygen atoms.
As a general rule of thumb, Compounds that involve a metal bond with a nonmetal or semimetal exhibit ionic bonding. Compounds consisting only of nonmetals or semimetals with nonmetals show a covalent bond and are classified as molecular compounds.