All materials are made up of atoms. These atoms are held together by forces called interatomic bonds. The bonds act like springs, linking each atom to its neighbour.

atom

There are several different types of bonds that form between atoms. The type of bonding between atoms can give rise to very different properties. For example, graphite and diamond are both carbon, however, due to the nature of their atomic bonding, they exhibit exceptionally different material characteristics.

Atoms are arranged in different ways in different materials. Two important aspects of atomic packing are the number of bonds per unit area:

atom1

And the angle of bonding:

atom2

There are two important aspects of atomic packing.

The first is the bond length (animation below).

The second is the bond angle. Roll your mouse over the image to see a change in bond angle.