Solids are the state of matter which have definate shape,size and volume.It doesn't flow except mercury.

Solids: Mixtures and Pure Substances - Some Basic Concepts of Chemistry

Solids are one of the three main states of matter, along with liquids and gases. Solids have a definite shape and volume, with particles that are closely packed together.

Solids in Mixtures
- In mixtures, solids can be present in various forms such as suspension, colloid, or solution.
- Suspensions are mixtures where solid particles are dispersed in a liquid but eventually settle down due to gravity.
- Colloids are mixtures with solid particles dispersed in a liquid, but they do not settle down due to their small size and charge.
- Solutions are homogeneous mixtures where solid particles are dissolved in a liquid and do not settle down.

Solids in Pure Substances
- In pure substances, solids can exist in elemental form (e.g., gold, silver) or in compound form (e.g., salt, sugar).
- Pure substances have a specific chemical composition and properties, which distinguish them from mixtures.
- The arrangement of particles in a solid determines its physical properties such as hardness, density, and melting point.

Characteristics of Solids
- Solids have a definite shape and volume, which is due to the strong forces of attraction between particles.
- The particles in solids are arranged in a regular pattern, leading to a crystalline structure in many cases.
- Solids can exist in different forms such as crystalline solids (with a regular repeating pattern) or amorphous solids (without a regular pattern).

In conclusion, solids play a crucial role in mixtures and pure substances, showcasing unique properties and behaviors based on their composition and arrangement of particles. Understanding the nature of solids is essential for exploring the world of chemistry and its applications.