The key difference between a solid and a liquid lies in the structure and movement of their particles.
Which of these best describes the difference between a solid and a liquid?
Solids: Particles in solids are tightly packed and arranged in a regular, fixed pattern. They vibrate slightly but don't move around each other much. This strong, ordered structure gives solids their definite shape and volume. They resist changing shape and are generally rigid.
Liquids: Particles in liquids are also close together, but they have more kinetic energy and can move around each other more freely. This means they have a definite volume but no definite shape. They take the shape of their container and can flow easily.