Explain the terms rigidity, compressibility, and fluidity.

Differences Between Rigidity, Compressibility, and Fluidity

What is Rigidity?

Rigidity is the property of a substance that resists a change in shape when an external force is applied. Substances with high rigidity do not easily bend, stretch, or compress. Solids exhibit maximum rigidity because their particles are closely packed and have strong intermolecular forces. For example, a steel rod maintains its shape even under pressure due to its high rigidity.

Rigidity Key point: Solids are highly rigid; gases and liquids have very low rigidity.

Also Check: Types of Intermolecular Forces

What is Compressibility?

Compressibility refers to the ability of a substance to decrease in volume when pressure is applied. Gases are highly compressible because the particles are far apart and can be pushed closer together. Liquids have very low compressibility, and solids are almost incompressible.

Compressibility Key point: Gases are the most compressible; solids are least compressible.

What is Fluidity?

Fluidity is the ability of a substance to flow and change shape without breaking. Both liquids and gases are fluids because they can flow easily due to weak intermolecular forces. Solids generally lack fluidity as their particles are tightly bound.

Fluidity Key point: Liquids and gases exhibit fluidity; solids do not.

Comparison Between Rigidity, Compressibility and Fluidity

• Rigidity → Resistance to shape change (highest in solids).
• Compressibility → Ability to reduce volume under pressure (highest in gases).
• Fluidity → Ability to flow (present in liquids and gases).