1. Fig. 16-12 A diatomic molecule. Almost all the mass of each atom is in its tiny nucleus. (a) The center of mass has 3 independent velocity components. (b) The molecule has 2 independent axes of rotation through its center of mass. (c) The atoms and “spring” have additional kinetic and potential energies of vibration.

2. Fig. 16-13 Experimental values of Cv for hydrogen gas (H 2 ). Appreciable rotational motion begins to occur above 50 K, and above 600 K the molecule begins to appreciably increase its vibrational motion.

3. Fig. 16-14 The forces between neighboring particles in a crystal may be visualized by imagining every particle as being connected to its neighbors by springs.

4. Fig. 16-15 At high temperatures, Cv for each solid approaches approx. 3R, in agreement with the rule of Dulong and Petite.

5. Fig. 16-16 A molecule with a speed v passes through the first slit. When is reaches the second slit, the slits have rotated rotated through the offset angle . If v =  x / , the molecule passes through the second slit and reaches the detector.

6. Fig. 16-17 Curves of the Maxwell-Boltzmann distribution function f(v) for various temperatures. As the temperature increases, the curve becomes flatter and its maximum shifts to higher speeds. (b) At temperature T 3 the fraction of molecules having speeds in the range v 1 to v 2 is shown by the shaded area under the T 3 curve. The fraction with speeds greater than v A is shown by the area from v A to infinity.