kinetic theory of matter
the molecules of an object move faster as the object is heated.
thermal energy
an object's internal energy due to the random motions of its individual molecules
thermal equilibrium
the state in which no thermal energy is transferred between objects because they are at the same temperature
heat
the transfer of thermal energy from an object of higher temperature to an object of lower temperature
heat capacity
the amount of heat needed to change its temperature by a certain amount
specific heat
the amount of heat needed to cause a unit rise in the temperature of a unit mass of the substance
calorimeter
the device designed to measure the heat involved in physical and chemical changes
thermostat
device that automatically regulates temperature
conduction
the process by which heat flows through materials and between objects in direct contact
convection
the transfer of heat by moving fluids
convection currents
currents within the liquid caused by heated fluid rising and cooler fluid sinking
radiation
the transfer of energy as radient energy
thermodynamics
the branch of physics that deals with thermal energy, heat, and thier relationships to other forms of energy and energy transfer
first law of thermodynamics
The idea that the energy gained (or lost) by a system is equal to the energy lost (or gained) by its surroundings.
second law of thermodynamics
the idea that natural processes tend to go only toward less usable energy and greater disorder
entropy
a measure of the amount of disorder in a system
heat of fusion
the latent heat required to change a given mass of a solid into a liquid without changing its temperature
evaporation
the change from a liquid into a gas
volatile
liquids that evaporate rapidly
nonvolatile
liquids that evaporate slowly
the refrigerant, compressor, condenser, and evaporator
the four main components of a heat pump
system
the matter or portion of the universe being studied
surrounding
the entire universe except the system
mechanical equivalent of heat
the relationship between mechanical energy and heat
the Carnot engine
a theoretical device that would generate the maximum possible amount of work from a given amount of heat
freezing point
the temperature at which a liquid turns into a solid
boiling
when evaporation occurs throughout a liquid
heat of vaporization
the quantity of heat required to change a given amount of liquid already at its boiling point into a gas without raising its temperature
heat pumps
devices that use mechanical energy and latent heat to transfer thermal energy from a colder location to a warmer location
sublimation
when a substance skips the liquid state and changes directly into a gas
deposition
when a gas changes directly into a solid
plasma
state of matter that exists when temperatures are too high for matter to exist in its ordinary state