Final answer:
True, the particles of a more dense substance are closer together, contributing to their higher densities compared to less dense substances where particles are more separated.
Step-by-step explanation:
True, the particles of a more dense substance are indeed closer together. This concept is essential when understanding the properties of matter in different states. Density is defined as mass per unit volume. In solids and liquids, atoms and molecules are packed tightly, contributing to their higher densities compared to gases, where the particles are separated by empty space. For instance, if the distance between atoms and molecules in a substance increases by a factor of 10, the volume it occupies increases by a factor of 1000, causing the density to decrease by the same factor, which is evident in the transition from liquid or solid to gas.
This relationship between volume, mass, and density also affects other properties like the melting point and compressibility of substances. Materials with higher density typically have a structure where particles are in close contact. This structural tightness also makes them nearly incompressible, which in turn affects how sound travels through them, with sound speeds being slower in more compressible media.