Solids are generally very heavy while gases are generally very light. Explain.

The particles in a solid are closely packed and arranged orderly. The intermolecular spaces between the particles are very less. Therefore, the density of particles in a solid is very high whereas the volume is less. Hence solids are heavy.

The particles in a gas are arranged loosely and disorderly. The intermolecular spaces between the particles are too large. Therefore, the density of particles in a gas is much less whereas the volume is larger. Hence gases are generally light.

Explanation: -

Solids are generally heavy as compared to gases. In solids, atoms are very closely packed and have strong intermolecular forces of attraction. Due to which a large number of atoms lies in very less area.

While in case of gases atoms are in random motion and repel each other due to which the same number of atoms as in case of solid occupies large space and hence have low mass.