SOLIDS AND MODERN MATERIALS

Modern devices like computers and cell phones are built from solids with very specific physical properties. For example, the integrated circuit that is at the heart of many electronic devices is built from semiconductors like silicon, metals like copper, and insulators like hafnium oxide. 

Solids can be as hard as diamond or as soft as wax. Some readily conduct electricity, whereas others do not. The shapes of some solids can easily be manipulated, while others are brittle and resistant to any change in shape. The physical properties as well as 

1 CLASSIFICATION OF SOLIDS We see that solids can be classified according to the types of bonding interactions that hold the atoms together. This classification helps us make general predictions about the properties of solids. 

2 STRUCTURES OF SOLIDS We learn that in crystalline solids the atoms are arranged in an orderly, repeating pattern but in amorphous solids this order is missing. We learn about lattices and unit cells, which define the repeating patterns that characterize crystalline solids. 

3 METALLIC SOLIDS We examine the properties and structures of metals. We learn that many metals have structures in which the atoms pack together as closely as possible. We examine various types of alloys, materials that contain more than one element and display the characteristic properties of a metal. 

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