4. Solids

4. Solids

Concept Explanation:

Solids are materials characterized by their structural rigidity and resistance to changes in shape and volume. The particles in a solid are closely packed together, and the forces between them are strong, resulting in a fixed shape and volume.

Key Properties of Solids:
1. Crystalline Solids: Solids that have an orderly, repeating pattern of atoms or molecules, such as salts and metals.
2. Amorphous Solids: Solids that lack a well-defined structure, such as glass and plastics.

Example Problem:

Describe the difference between crystalline and amorphous solids, giving examples of each.

Solution:

Crystalline Solids: These have a highly ordered arrangement of atoms or molecules in a repeating pattern. Examples include table salt (sodium chloride) and diamond.

Amorphous Solids: These lack a long-range order in the arrangement of their particles. Examples include glass and rubber.