Why some glasses break suddenly while others deform smoothly‎

If a liquid is cooled slowly to its freezing point, it becomes a crystal in which the constituent particles are arranged in an ordered pattern. In contrast, when the liquid is cooled very quickly, the particles are unable to arrange themselves in an ordered fashion, and it becomes glass. Glassy materials are all around us in everyday life. Common examples include window glass, certain metal alloys, polymers, foams, gels and even soft materials like emulsions and colloids.