Covalent Bonding

Covalent substances with simple molecular substance

• Low melting point and boiling points → they have simple molecular structures with weak intermolecular forces of attraction. Little energy is needed to overcome these forces. Thus, these compounds have low melting and boiling points.

• Insoluble in water and soluble in organic solvents

• Do not conduct electricity in any state → they exist as molecules, hence there are no ions or electrons to carry charges.

Diamond

Each carbon atom is bonded to 4 other carbon atoms by strong covalent bonds in a tetrahedral arrangement

Graphite

Each carbon atom is bonded to 3 other carbon atoms by strong covalent bonds in a layers of hexagonal rings. Each layer of carbon are held together by weak forces of attraction

Silicon Dioxide

Each silicon atom is bonded to oxygen atoms and each oxygen atoms and each oxygen atom is bonded to 2 silicon atoms by strong covalent bonds.

Diamond properties

• High melting points and boiling points → They have a giant covalent structures with a giant network of strong covalent bonds between the carbon atoms that extend throughout the structure. A lot of energy is needed to break those bonds. Thus, diamond has a high melting and boiling point

• Hard and strong → They have a giant covalent structures with a giant network of strong covalent bonds between the carbon atoms that extend throughout the structure. A lot of energy is needed to break those bonds. Thus, diamond is very hard and strong and is used as tips of drilling tools.

• Cannot conductor electricity in all states → Each carbon atom is covalently bonded to 4 other carbons atoms. Hence, there are no free mobile electrons to carry charges and conduct electricity

Graphite properties

• High melting point and boiling point→ They have a giant covalent structures with a giant network of strong covalent bonds between the carbon atoms that extend throughout the structure. A lot of energy is needed to break those bonds. Thus, graphite has a high melting and boiling point.

• Soft and slippery. Little energy is needed to overcome the weak forces of attraction between the carbon atoms. Layers of carbon atoms can slide past one another easily when a force is applied. Thus, graphite is soft and slippery and can be used as dry lubricant for machines.

• Conduct electricity in all states→ each carbon atom is bonded to 3 other carbon atoms, leaving 1 valence electron per carbon day atom which sod mobile. Hence, there are mobile electrons to carry charges.