Characteristics of Solid State
Characteristics of the Solid State
The solids are characterized by incompressibility, rigidity and mechanical strength. The molecules, atoms or ions in solids are closely packed, i.e., they are held together by strong forces and cannot move about atrandom. Thus solids have definite volume, shape, slow diffusion, low vapour pressure and possess the unique property of being rigid. Such solids are known as true solids.
E.g. NaCl, KCL, Sugar, Ag, Cu, etc.
On the other hand the solid which loses shape on long standing, flows under its own weight and is easily distorted by even mild distortion force is called pseudo solid e. g. glass, pith etc.
Some solids such as NaCl, sugar, sulphur etc. have properties not only of rigidity and incompressibility but also of having typical geometrical forms. These solids are called crystalline solids. In such solids there is definite arrangement of particles (atoms, ions or molecules) throughout the entire three dimensional network of a crystal. This is named as long-range order.
This three dimensional arrangement is called crystal lattice or space lattice. Other solids such as glass, rubber, plastics etc. which have rigidity and incompressibility to a certain extent but they do not have definite geometrical forms or do not have long-range order are known as amorphous solids.