Crystalline Solids
- This range of solids consists of a broad range of small crystals having a definite characteristic geometrical shape.
Fig. Crystals are crystalline solids
- The constituent particles are arranged in a long range order (symmetry and regularity of arrangement of constituent particles that repeat at any distance from a given atom due to the interaction between the particles) with a regular and periodically repeating pattern over the entire crystal.
- Crystalline solids possess a sharp melting point.
- Crystalline solids are anisotropic in nature due to different arrangement of particles in different directions. This leads to different value of physical property along different directions in the same crystals.
- Metallic elements including iron, copper and silver are typical examples of crystalline solids.
- On the other hand non – metallic elements like sulphur, phosphorus and iodine and compounds like sodium chloride, zinc sulphide and naphthalene and quartz are typical examples of crystalline solids.
Fig. Crystalline form of Sodium Chloride
- These solids can be further be into four categories the basis of the nature of intermolecular forces acting over them
Molecular solids
Ionic solids
Metallic solids
Covalent solids
