Chapter 17: Temperature and Heat

Temperature measurement is explored through various scales including Celsius, Fahrenheit, and Kelvin, with emphasis on absolute temperature and the triple point of water as a reference standard. Thermal expansion phenomena are examined through linear and volumetric expansion equations, demonstrating how materials change dimensions with temperature variations and how constrained expansion creates thermal stress. The distinction between heat and temperature is clarified, where heat represents energy transfer due to temperature differences while temperature measures average molecular kinetic energy. Specific heat capacity and molar heat capacity quantify how much thermal energy materials require for temperature changes, with Dulong and Petit's law providing insights into solid materials. Calorimetry principles govern energy conservation in thermal systems, while phase transitions reveal how materials absorb or release latent heat during melting, vaporization, and sublimation without temperature change. Heat transfer occurs through three primary mechanisms: conduction via molecular contact following Fourier's law, convection through fluid motion that can be natural or forced, and radiation through electromagnetic waves governed by the Stefan-Boltzmann law for blackbody emission and modified by emissivity for real materials.