fig. 10-1 The face-centered-cubic crystal structure of sodium chloride.

fig. 10-2 The body-centered-cubic crystal structure of cesium chloride.

fig. 10-3 The crystal lattice of diamond. The carbon atoms are held together by covalent bonds, which are shared electron pairs.

fig. 10-4 Graphite is a form of carbon that consists of layers of carbon atoms in hexagonal arrays. The layers are held together by the weak van der Waals forces described in Sec. 10-3.

fig. 10-6 The motion of a dislocation (line of missing particles) in a crystalline solid results in a permanent change in the shape of the solid.

fig. 10-7 The electron distribution in a water molecule is such that the end where the H atoms are attached behaves as if positively charged and the opposite end behaves as if negatively charged. The water molecule is therefore polar.

fig. 10-8 Polar molecules attract each other.

fig. 10-9 Polar molecules attract normally nonpolar molecules.

fig. 10-10 Nonpolar molecules normally have, on the average, uniform distributions of charge, but at any one moment the distributions may be uneven. When two nonpolar molecules are close together, the fluctuations in their charge distributions keep in step, which leads to an attractive force between them.

fig. 10-12 The solubility of NaCl is 36 g per 100 g of water at 20°C. (a) 30 g of NaCl in 100 g of water produces an unsaturated solution. (b) 36 g of NaCl is the maximum amount that can dissolve, and it produces a saturated solution. (c) If 40 g of NaCl is added to 100 g of water, 4 g will remain undissolved.

fig. 10-13 How the solubilities of various compounds in water vary with temperature. The higher the temperature, the greater the solubility.

fig. 10-14 The solubility of potassium nitrate, KNO₃, is 136 g per 100 g of water at 70° C and 31 g at 20° C. Cooling a saturated solution of KNO₃ from 70° C to 20° C causes 136 g — 31 g = 105 g of the salt per 100 g of water to crystallize out.

fig. 10-15 The higher the pressure and the lower the temperature, the greater the solubility of a gas in water.

fig. 10-16 Water molecules cluster together because of electric forces that arise from their polar character.

fig. 10-17 Sugar dissolved in water. Polar compounds readily dissolve in water because their molecules can link up with water molecules.

fig. 10-18 Gasoline dissolves fat; water does not. Nonpolar compounds dissolve only in nonpolar liquids.

fig. 10-19 Soap and detergent molecules are polar at one end and nonpolar at the other. The nonpolar ends become attached to a dirt particle to form a spherical cage around it called a micelle. Because the outside of a micelle is polar, it readily becomes suspended in water. By forming micelles around dirt particles, soap and detergent molecules remove them from dirty surfaces, and the micelles can then be rinsed away with water, taking the dirt with them.

fig. 10-20 Solution of sodium chloride crystal in water. Water molecules exert electric forces on the Na⁺ and Cl^- ions that are strong enough to remove them from the crystal lattice.

fig. 10-21 (a) An electrolyte such as NaCl in solution conducts electric current through the motion of its ions. (b) Pure water is nonelectrolyte, as are solutions of compounds that do no dissociate.

fig. 10-23 The composition of seawater. In the open ocean the total salt content varies about an average of 3.6 percent, but the relative proportions of the various ions are quite constant. (Percentages given are by mass.)

fig. 10-24 Origins of seawater salts.

fig. 10-25 A model of the hydronium ion, H₃0⁺.

fig. 10-26 Typical pH values.