ABSTRACT

Temperature and heat capacity are two properties that are easy to measure, but not so easy to conceptualize. In this chapter, we develop a conceptual picture of temperature, heat capacity, and related quantities. We use two simple models: the ideal gas, and the two-state Schottky model of Chapter 10. Two-state systems can have negative temperatures (lower than T = 0 K). Negative temperatures help to illuminate the meanings of temperature and heat capacity in general.