Question

analyzing ideas when a solid melts, its density does not change very much. so, why do a liquid and a solid have such different physical properties?

Explanation:

When a solid melts, although density doesn't change much, the physical properties differ. In solids, particles are in fixed positions with strong forces, leading to definite shape and volume. In liquids, particles can move more freely (while still close - packed, so density change is small), allowing liquids to flow and take the shape of their container. These differences in particle arrangement and movement (due to intermolecular forces and energy states) cause the distinct physical properties.

Answer:

The physical properties of a solid and liquid are different because of the difference in the arrangement and movement of particles. In a solid, particles are in fixed positions (due to strong intermolecular forces), giving it a definite shape and volume. In a liquid, while the density (as particles are still close - packed) doesn't change much from the solid state, the particles can move more freely (less restricted by intermolecular forces compared to solids), allowing liquids to flow and take the shape of their container.