When the pressure on a solid is greatly increased, the volume of the solid shows almost no change.

The volume of the solid shows no change

Explanation:

Pressure only affects gaseous system. This is because the force of cohesion between the gaseous molecules are negligible(i.e very small) and their molecules are far apart hence the gaseous molecules are easily compressed. But for solid, the Particles are very close and tightly packed together with a strong force of cohesion hence pressure has no effect on it. This account for the definite shape and definite volume of solid

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).