Considering crystals

Description: Looks at the way a molecular structure can build up through the repeated unit cell into a crystal lattice. Explains the main types of bonding which produce different types of crystal structure; it then goes on to consider some of the ways in which crystal structure is controlled in practice. The film illustrates its points with examples ranging from the alloying of steel and copper to the control of polymorphism in fats and the crystalline structure of polymers in plastics and man-made fibres.