Physical Science - Chapter 15

Thermodynamics

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

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

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