Chemistry – States of matter - Solids, liquids and gases | e-Consult

Solids: In a solid, particles are very closely packed together in a fixed, regular arrangement. This arrangement can be crystalline (repeating pattern) or amorphous (no repeating pattern). The separation between particles is very small. The particles in a solid vibrate about fixed positions, but they do not move past each other. Strong intermolecular forces (e.g., ionic bonds, covalent network, metallic bonds, or strong van der Waals forces) hold the particles in place. This strong attraction is what gives solids their definite shape and volume.

Liquids: In a liquid, particles are still close together, but they are not in a fixed arrangement. The particles are randomly arranged and can move past each other. The separation between particles is greater than in a solid. The particles in a liquid vibrate and slide past each other. Intermolecular forces are weaker than in solids (e.g., van der Waals forces, hydrogen bonding). This allows liquids to flow and take the shape of their container, but they still maintain a definite volume.

Gases: In a gas, particles are widely separated and randomly arranged. The separation between particles is large. The particles move randomly and rapidly in all directions. The particles in a gas have very weak intermolecular forces, allowing them to move freely and fill the entire volume of their container. Gases have neither a definite shape nor a definite volume.