1.51

know that covalent compounds do not usually conduct electricity 

Covalent compounds don’t conduct electricity as they don’t have a delocalized electrons so aren't free to move to conduct an electric charge 

1.50

Explain How the Structures of Diamond, Graphite and C60 Fullerene Influence their Physical properties, Including Electrical Conductivity and Hardness  

Diamond:  

Hard; each carbon atom is joined to another four carbon atoms forming a giant covalent structure which is difficult to break.  

High melting and boiling points: as of the giant covalent structure there are so many bonds that need to be broken so large amount of heat is needed 

Doesn’t conduct electricity: as there are no delocalized electrons so aren't free to move to  

Used to cut glass  

Graphite: 

Soft: weak delocalized electrons in-between layers that can be easily separated 

High melting and boiling points: as of the giant covalent structure there are so many bonds that need to be broke so large amount of heat is needed 

Does conduct electricity: as of the interlocking hexagons only 3 electrons are used so the fourth is free to move 

Used as lubricant  

Fullerene C60: 

Soft: each carbon atom is joined to three other carbon atoms so there are weak intermolecular forces or attraction so they can be easily broken 

Low melting and boiling points:  each carbon atom is joined to three other carbon atoms so there are weak intermolecular forces of attraction so little heat energy is needed to break them 

Does conduct electricity: as of only 3 electrons are used so the fourth is free to move 

Used as a drug delivery system in the body