States of Matter:
Variation in the characteristics of the particles of matter leads to various states of matter:
- It is one of the fundamental states of matter.
- Solids can be defined as the state of matter which has definite shape and volume and has a rigid structure.
- Solids are most rigid, least compressible and show least thermal expansion among the three states.
- Solids have high density.
- The molecules of solids are tightly packed because of strong intermolecular forces.
- So, they only oscillate about their mean positions.
- On the other hand, liquids and gases possess the property of fluidity and can easily flow.
- Examples: Sugar, sand, iron, wood, rocks, minerals and ice.
Why do Solids, Liquids and Gases have Different Properties?
The following properties of particles decide whether a given substance will exist as a solid, a liquid or a gas:
- The spaces (or distances) between the particles. The spaces (or distance) between the particles are the minimum in solids, a little more in liquids, and the maximum in gases.
- The force of attraction between particles. The forces of attraction between the particles (or interparticle forces) are the strongest in solids, less strong in liquids and negligible in gases.
- The amount of movement of particles (or kinetic energy of particles). The movement of particles (or kinetic energy of particles) is the minimum in solids, more in liquids and the maximum in gases.