physics chap13

• Absolute zero


  The lowest possible temperature; the temperature at which all molecular motion ceases
• Avogadro's number NA


  The number of molecules or atoms in one mole of a substance; NA= 6×1023 particles/mole
• Boltzmann constant k


  A physical constant that relates energy to temperature
• Celsius scale


  Temperature scale in which the freezing point of water is 0°C and the boiling point of water is 100°C
• Coefficient of linear expansion α


  The change in length, per unit length, per 1°C change in temperature; a constant used in the calculation of linear expansion; the coefficient of linear expansion depends on the material and to some degree on the temperature of the material
• Coefficient of volume expansion β


  The change in volume, per unit volume, per 1°C change in temperature
• Critical point


  The temperature above which a liquid cannot exist
• Critical pressure


  The minimum pressure needed for a liquid to exist at the critical temperature
• Critical temperature


  The temperature above which a liquid cannot exist
• Dalton's law of partial pressures


  The physical law that states that the total pressure of a gas is the sum of partial pressures of the component gases
• Degree Celsius


  Unit on the Celsius temperature scale
• Degree Fahrenheit


  Unit on the Fahrenheit temperature scale
• Dew point


  The temperature at which relative humidity is 100%; the temperature at which water starts to condense out of the air
• Fahrenheit scale


  Temperature scale in which the freezing point of water is 32°F and the boiling point of water is 212°F
• Ideal gas law


  The physical law that relates the pressure and volume of a gas to the number of gas molecules or number of moles of gas and the temperature of the gas
• Kelvin scale


  Temperature scale in which 0 K is the lowest possible temperature, representing absolute zero
• Mole


  The quantity of a substance whose mass (in grams) is equal to its molecular mass
• Partial pressure


  The pressure a gas would create if it occupied the total volume of space available
• Percent relative humidity


  The ratio of vapor density to saturation vapor density
• Phase diagram


  A graph of pressure vs. temperature of a particular substance, showing at which pressures and temperatures the three phases of the substance occur
• PV diagram


  A graph of pressure vs. volume
• Relative humidity


  The amount of water in the air relative to the maximum amount the air can hold
• Saturation


  The condition of 100% relative humidity
• Sublimation


  The phase change from solid to gas
• Temperature


  The quantity measured by a thermometer
• Thermal energy KE


  The average translational kinetic energy of a molecule
• Thermal equilibrium


  The condition in which heat no longer flows between two objects that are in contact; the two objects have the same temperature
• Thermal expansion


  The change in size or volume of an object with change in temperature
• Thermal stress


  Stress caused by thermal expansion or contraction
• Triple point


  The pressure and temperature at which a substance exists in equilibrium as a solid, liquid, and gas
• Vapor


  A gas at a temperature below the boiling temperature
• Vapor pressure


  The pressure at which a gas coexists with its solid or liquid phase
• Zeroth law of thermodynamics


  Law that states that if two objects are in thermal equilibrium, and a third object is in thermal equilibrium with one of those objects, it is also in thermal equilibrium with the other object