Heat and Heat Technology
____ is a measure of the average kinetic energy of the particles in an object. Temperature
Because particles are in motion, they have kinetic energy.
The motion of particles in a substance is random.
____ is the increase in volume of a substance due to an increase in temperature. Thermal expansion
Alcohol in a thermometer rises as a result of thermal expansion.
The lowest temperature on the Kelvin scale is absolute zero.
Absolute zero is 0 K.
Some bridges are constructed with small gaps called expansion joints because concrete segments expand on hot days.
____ is the transfer of energy between objects that are at different temperatures. Heat
The total kinetic energy of the particles that make up a substance is thermal energy.
At ____, no net change in either object’s thermal energy occurs. thermal equilibrium
The ____ are the physical forms in which a substance can exist. states of matter
The transfer of thermal energy from one substance to another through direct contact is conduction.
The handle of a metal spoon warms up when it is placed in a hot bowl of soup because of conduction.
Good conductors are made of metal.
Good insulators are made of wood, cloth, and rubber.
The transfer of thermal energy by the movement of a liquid or a gas is convection.
The transfer of thermal energy through space is radiation.
Farmers grow vegetables in winter using greenhouses, which receive heat by radiation.
Warming up beside a campfire is an example of radiation.
Particles of a _____ do not move fast enough to overcome the strong attraction between them, so they are held tightly together. solid
Particles of a _____ vibrate in place. solid
Particles move slowest in a solid.
Particles of a _____ move fast enough to overcome some of the attraction between them. liquid
Particles of a _____ are able to slide past one another. liquid
Particles of a _____ move fast enough to overcome nearly all of the attraction between them. gas
Particles of a _____ move independently of one another. gas
A change of state is a physical change.
A ____ affects one or more physical properties of a substance without changing the substance’s identity. physical change
When one or more substances are changed into entirely new substances with different properties a ____ has occurred. chemical change.
____ is a substance that reduces the transfer of thermal energy. Insulation