# 15A Temperature

• Temperature: the measure of the hotness or coldness of a substance; proportional to the average kinetic energy of the particles within the substance

• Thermometric Property: any property that changes predictably with changes in temperature

• Thermal Expansion: the property of many materials to increase in volume when heated and contract when cooled

• Temperature Scales

• Fahrenheit

• Celsius

• Kelvin

# 15B Heat

• Heat: movement of thermal energy from an area of higher temperature to one of lower temperature

• Energy Transfer

• Conduction: movement of electric charge or thermal energy through an object or from object to object through direct contact

• Convection: movement of thermal energy as fluids move

• Radiation: movement o energy in the form of electromagnetic waves

• Thermal Conductor: a material through which thermal energy moves easily

• Thermal Insulator: a material through which thermal energy does not easily move

• Measuring Heat

• Specific heat: the energy required to raise the temperature of 1 g of a substance 1 degree Celsius

• Calorimeter: a device that enables scientists to measure the thermal energy transferred in reactions and between systems

• Energy Transfer By Heating

• Heating ice

• Melting ice

• Heating water

• Vaporizing water

• Heating steam

# 15C Thermodynamics

• Thermodynamics: the study of thermal energy and heat and how they relate to work and other forms of energy

• Caloric Theory: the now-obsolete theory that stated that heat was an invisible self-repelling fluid

• Laws of Thermodynamics:

• First Law of Thermodynamics: the law that states that energy cannot be created or destroyed but only transferred between objects or transformed; also known as law of conservation of energy

• Second Law of Thermodynamics: the law that states that energy can flow from a colder object to a warmer object only if something does work

• Third Law of Thermodynamics: the law that states that entropy would be at its minimum value at absolute zero. Therefore, absolute zero can never be achieved