Question

Distinguish between solids, liquids and gases on the basis of their expansion on heating.

Answer 1

When a solid is heated, its atoms vibrate faster about their fixed points. The relative increase in the size of solids on heating is therefore small. Liquids expand for the same reason, but because the bonds between separate molecules are usually less tight, they expand more than solids. Molecules in a gas are far apart with the least intermolecular force. Heat causes the molecules to move faster, which means that the volume of a gas increases more than the volume of a solid or liquid.