Flexi Says: In general, solids tend to be denser than liquids, and liquids denser than gases. This is because particles (e.g., atoms and molecules) tend to be packed closest together in solids, while in gases the particles spread out. However, there are many exceptions to this rule. For example, some solid foam materials are less dense than water. Gases can be compressed in high pressure containers to become more dense than some liquids.
