A MOLECULAR COMPARISON OF GASES, LIQUIDS, AND SOLIDS

As we learned in Chapter 10, the molecules in a gas are widely separated and in a state of constant, chaotic motion. One of the key tenets of kinetic-molecular theory is the assumption that we can neglect the interactions between molecules. (Section 10.7) The properties of liquids and solids are quite different from gases largely because the intermoiecuiar forces in liquids and solids are much stronger. A comparison of the properties of gases, liquids, and solids is given in TABLE 11.1. 

Assumes both volume and shape of its container Expands to fiU its container Is compressible Flows readily 

Assumes shape of portion of container it occupies Does not expand to fiU its container Is virtually incompressible Flows readily 

Diffusion within a solid occurs extremely slowly 

---

FIGURE 10.1 A molecular comparison of gases, liquids, and solids, (a) In gases, the particles feel little attraction for one another and are free to move about randomly, (b) In liquids, the particles are held close together by attractive forces but are free to move over one another, (c) In solids, the particles are rigidly held in an ordered arrangement. 

SECTION 11.1 A Molecular Comparison of Gases, Liquids, and Solids 427... 

A MOLECULAR COMPARISON OF GASES, LIQUIDS, AND SOLIDS We begin with a comparison of solids, liquids, and gases from a molecular perspective. This comparison reveals the important roles that temperature and intermolecular forces play in determining the physical state of a substance. 

---