With the exception of water, the solid form of matter is: more dense than the liquid form less dense than the liquid form equal in density to the liquid form
physics

The closer together the molecules are, the more dense it is going to be.
With this being said solid would be the most dense compared to the water and gas because when something is solid the molecules are cramped-like together, tightly packed.
The solid form of matter is more dense than the liquid.
Density Scale: (>) means more dense..
Solid > Water
Solid > Gas
Water > Gas

The answer to this is decibel