Solids | General Properties

The substances which are rigid, hard, have definite shape and definite volume are called solids.

General Properties Of Solids

1. Rigidity of Solids

The atoms, ions or molecules of a solid do not possess sufficient energy to move about nor take up different positions like the molecules of a gas or a liquid. They have fixed positions. The rigidity of a solid may be changed under stress. Due to stress a solid can shatter and such solids are called brittle. Glass is one of the best examples. Alternatively a stress can make the solids to spread out into a thin sheet and such solids are malleable.

2. Definite Volume

The atoms, ions or molecules of a solid are close to each other and are held together by intermolecular forces. There is not much free space between them, enabling them to have a definite volume.

3. Low Compressibility

The particles in solids are tightly held. As a result solids are difficult to compress.

4. High Density

The close packing of the particles in the solids eliminates the free space between them to show high density.

5. Diffusion

The diffusion of a solid into another solid is very slow as compared to liquids or gases. The reason is that atoms of solids have fixed positions from which they cannot move appreciably.

6. Vapour Pressure

The vapour pressures of solids are remarkably less than those of liquids, the reason being the stronger forces of attractions in solids as compared to liquids.

7. Melting

When a solid is heated, the atoms, ions or molecules present in a solid start vibrating at a higher frequency and transfer their kinetic energy throughout the solid. At the melting point of the solids their vibrational frequency increases so much that they leave their fixed positions and collapse to become a liquid.