Why do solids have a definite volume?

Solids have a definite volume because their particles are tightly packed and held together by strong intermolecular forces, which prevent them from moving freely.

In science, matter is classified into three main states: solid, liquid, and gas. Among these, solids are unique because they have both a fixed shape and a fixed volume. The reason behind this lies in the arrangement and behavior of the particles inside them.

Structure of Solids

• Particles in solids are very close to each other.
• They are held by strong intermolecular forces of attraction.
• They cannot move freely but only vibrate in their fixed positions.

Why Solids Retain Volume

Because the particles cannot move away from each other, the overall distance between them does not change. This keeps the size and space occupied by the solid constant, giving it a definite volume. Unlike liquids or gases, solids do not expand or compress easily under normal conditions.

Examples

• A stone keeps the same size no matter where it is placed.
• An ice cube remains the same volume until it melts.