Solids

• Particles are closely packed in a fixed, regular arrangement.
• Strong intermolecular forces hold them together.
• Particles vibrate in place but do not move freely.
• Solids have a fixed shape and fixed volume.
• Incompressible due to minimal space between particles.

Liquids

• Particles are close together, but not in fixed positions.
• Weaker intermolecular forces than solids.
• Particles can slide past each other, allowing the liquid to flow.
• Liquids have a fixed volume but no fixed shape — they take the shape of their container.
• Slightly compressible, but not easily.

Gases

• Particles are far apart and move freely and randomly.
• Very weak or negligible intermolecular forces.
• Gases have no fixed shape and no fixed volume — they fill any container.
• Highly compressible because of large spaces between particles.
• Exhibit diffusion and expansion rapidly.

Plasma

• Consists of ionized particles — a mix of positive ions and free electrons.
• Forms at extremely high temperatures or under strong electromagnetic fields.
• Commonly found in stars, lightning, and neon signs.
• Conducts electricity and responds to magnetic fields.
• No fixed shape or volume — behaves similarly to gases but with charged particles.

Written by Thenura Dilruk