Chapter 6 Flashcards
What is the internal energy that an object has because of the random motions of its individual molecules?
thermal energy
What is closely related to the thermal energy of an object?
temperature
What are three factors that affect the thermal energy of an object?
Mass, state of matter, and temperature
What is the transfer of thermal energy from an object of higher temperature to an object of lower temperature?
heat
How is heat measured?
using the joule
What is the state in which no thermal energy is transferred between objects because they are at the same temperature?
thermal equilibrium
What is the amount of heat needed to change an object’s temperature by a certain amount?
heat capacity
What is the ratio of an object’s heat capacity to the object’s mass?
specific heat
What is a device designed to measure the heat involved in physical and chemical changes?
calorimeter
What is a device that automatically regulates temperature?
thermostat
What is a device consisting of two metal strips that are bonded together that bends in response to temperature changes?
bimetallic strip
What is the transfer of a property like thermal energy (heat) or electric charge through direct contact?
conduction
Who invented the miner’s safety lamp?
Sir Humphrey Davy
What is a transfer of heat by moving fluids?
convection
What are currents within a liquid caused by heating fluids rising and cooler fluids sinking?
convection currents
What is a transfer of heat without matter as radiant energy?
radiation
What is a type of double-walled container designed to minimize the transfer of heat?
Dewer flask
What type of system warms a room by convection currents?
Hot-water heating systems
What type of system warms a room with a furnace?
forced- warm- air systems
What is the branch of physics that deals with thermal energy, and their relationships to other forms of energy and energy transfer?
thermodynamics
What is a matter or portion of the universe being studied?
system
What is the entire universe except the system?
surroundings
What is the relationship between mechanical energy and heat?
mechanical equivalent of heat
What is the law stating that the energy gained (or lost) by a system is the equal to the energy lost (or gained) by its surroundings?
first law of thermodynamics
What is a theoretical device that would generate the maximum possible amount of work from a given amount of heat?
carnot engine
What is the law stating that natural processes tend to go only one way, toward less unusable energy and greater disorder; implies that the universe is not improving but running down?
second law of thermodynamics
What is the measure of the amount of disorder in a system?
entropy
What is a hypothetical machine that would work generate its own energy once set into motion?
perpetual motion machine
What is the changing of a solid into a liquid?
melting
What is the changing of a liquid into a solid?
freezing
What is the phenomenon in which the freezing point of a liquid is lowered by the addition of solutes?
freezing point depression
What is the “hidden” heat absorbed or released when a substance changes its state?
latent heat
What is the latent heat required to change a given mass of a solid into a liquid without changing its temperature?
heat of fusion
What is the change of a substance from a liquid into a gas?
evaporation
What describes a liquid that evaporates rapidly?
volatile
What describes a liquid that evaporates slowly?
nonvolatile
What is the state of evaporation that occurs throuhgout a liquid?
boiling
What is the temperature a which a substance boils?
boiling point
Who first measured the mechanical equivalent of heat?
James Prescott Joule
What is the phenomenon is which the addition of nonvolatile solutes raises the boiling point temperature of a liquid?
boiling point of elevation
What is the latent heat required to change a given amount of liquid already at its boiling point into a gas without changing its tempeature?
heat of vaporization
What is the process of a gas changing into a liquid?
condensation
What is the pressure that must be exerted by a vapor on a liquid of the same substance for the vapor and liquid to be in equilibrium at a given temperature?
vapor pressure
What is the temperature at which the vapor pressure equals the pressure of the air above the liquid?
boiling point
What is the temperature above which a substance cannot exist in the liquid state but behaves as a gas regardless of the pressure upon it?
critical temperature
What is a device that uses mechanical energy and latent heat to transfer thermal energy from a colder location to a warmer location?
heat pump
What is a fluid used to transfer thermal energy throughout a heat pump?
refrigerant
What is the part of a heat pump that compresses gaseous refrigerant to a very high pressure?
compressor
What is the radiation in a heat pump in which the refrigerant cools as it releases heat to its surroundings?
condensor
What is the winding tube in a heat pump in which some of the liquid changes instantly to vapor, absorbing much thermal energy as a latent heat and cooling dramatically?
evaporator
What is the process of a solid changing directly into a gas?
sublimation
What is the process of a gas changing driectly into a solid?
deposition
What is a special state of matter that is an ionized gas and exists when temperatures are too high for matter to exist in its ordinary state?
plasma
