The important properties of solid substances are as under-
Nature- The solids are of two types crystalline and non-crystalline or amorphous. In a crystalline substance, the atoms are arranged in a periodic, regular and definite geometrical form. Such substances have long-range orderliness and definite melting points. Example- metals, salts, etc. On the other hand, amorphous solids do not have a regular atomic arrangement and definite melting points. Such substances do not have long-range orderliness but have short-range orderliness. The examples of amorphous solids are glass, wood, flour etc.
Malleability- Solid substances which can be beaten into thin leaves or sheets are referred to as malleable. For instance, the metals like copper, silver, gold etc. can be hammered or rolled into sheets. Thus, malleability is a characteristic property of metals.
Ductility- The solids which can be drawn into wires on the application of force are known as ductile. For instance, metals like copper, silver and a few other substances possess this property.
Brittleness- This is a property by virtue of which the solids can be broken into pieces when struck. The solids like glass, alum, etc. possess this property.
Perfect Elasticity- A substance or body is considered to be perfectly elastic in nature if it entirely regains its original shape and size completely on the removal of deforming forces. No material body is yet known to be perfectly elastic in its behaviour. Only the nearest approach to perfectly elastic material is the quartz fibre.
Perfect Plasticity- All bodies get deformed on the application of a certain amount of force. A body which does not regain its original shape and size after the removal of deforming force is referred to as a plastic body. Plasticity is the property by virtue of which a body retains its deformed shape and size after the removal of deforming force. No material body is perfectly plastic in nature. As a matter of fact, all bodies show a behaviour intermediate between the phenomenon of perfect elasticity and perfect plasticity.