Solids are generally denser than liquids and gases because:

i. The space between the constituent particles of solid is less than that of liquids and gases.

ii. The force of attraction between the particles is maximum.

iii. Hence, large mass is concentrated in a very small volume.

iv. Larger will be the mass, greater will be the density.

v. In case of liquids and gases, there is so much space between the particles.

vi. Hence they don’t have large mass which is concentrated in a very small volume.

vii. So the density of solids is general more than liquids and gases.