Solids have the highest density among the three, gases have the lowest, and liquids are slightly less dense than solids but much denser than gases. the 3 states of matter are solid, liquid and gas. The density is related to the number of molecules in a given volume of space. If the molecules are compressed and at a lower energy level (ie solid), the density will be higher. If the molecules are further apart, due to a higher energy level (ie gas), the density will be lower.
