Answer to Question #158137 in General Chemistry for John

Question

Research and describe, using diagrams, the type of bonding and structure present in two allotropes of carbon.

Answer 1

In diamond, each carbon shares electrons with four other carbon atoms - forming four single bonds. In the diagram some carbon atoms only seem to be forming two bonds (or even one bond), but that's not really the case. This is a giant covalent structure - it continues on and on in three dimensions. It is not a molecule, because the number of atoms joined up in a real diamond is completely variable - depending on the size of the crystal. 

Graphite has a layer structure which is quite difficult to draw convincingly in three dimensions. The distance between the layers is about 2.5 times the distance between the atoms within each layer. The layers, of course, extend over huge numbers of atoms.