Structure of Metals
Solids have greater interatomic attractions than liquids and gases. However, there are wide
variations in the properties of solid materials used for engineering purposes. The properties of
materials depend on their interatomic bonds. These same bonds also dictate the space between
the configuration of atoms in solids. All solids may be classified as either amorphous or
Amorphous materials have no regular arrangement of their molecules. Materials like glass
and paraffin are considered amorphous. Amorphous materials have the properties of
solids. They have definite shape and volume and diffuse slowly. These materials also
lack sharply defined melting points. In many respects, they resemble liquids that flow
very slowly at room temperature.
In a crystalline structure, the atoms are arranged in a three-dimensional array called a
lattice. The lattice has a regular repeating configuration in all directions. A group of
particles from one part of a crystal has exactly the same geometric relationship as a group
from any other part of the same crystal.