Thermal Properties

thermostat

thermostat

a device used to regulate temperature

bimetallic strip

Strips of two metals having different coefficients of thermal expansion are bonded along their lengths

Thermal property

refers to the response of a material to the application of heat.

Heat capacity

represents the quantity of heat required to produce a unit rise in temperature for 1 mole of a substance

specific heat

quantity of heat required to produce a unit rise in temperature for 1 mole of a substance on a per-unit-mass basis,

phonon

a single quantum of vibrational energy

Thermal expansion

reflected by an increase in the average interatomic separation, which is a consequence of the asymmetric nature of the potential energy–versus– interatomic spacing curve trough

lower

The larger the interatomic bonding energy, the _____ the coefficient of thermal expansion

polymers

Values of coefficients of thermal expansion for _____ are typically greater than those for metals and ceramic materials

thermal conduction

The transport of thermal energy from high- to low-temperature regions of a material

heat

For solid materials, ____ is transported by free electrons and by vibrational lattice waves (phonons)

ceramics and polymers

_____ and _______ are poor thermal conductors because free-electron concentrations are low and phonon conduction predominates.

high thermal conductivities

The _______________ for relatively pure metals are due to the large numbers of free electrons and the efficiency with which these electrons transport thermal energy.

Thermal stresses

introduced in a body as a consequence of temperature changes, may lead to fracture or undesirable plastic deformation.

Heat capacity

indicates a material’s ability to absorb heat from the external surroundings; it represents the amount of energy required to produce a unit temperature rise.

Specific heat

represents the heat capacity per unit mass and has various units

phonon

a single quantum of vibrational energy

linear coefficient of thermal expansion

material property that is indicative of the extent to which a material expands upon heating and has units of reciprocal temperature

thermal shock

fracture as a consequence of nonuniform dimensional changes

thermal conductivity

property that characterizes the ability of a material to transfer heat

Thermal stresses

stresses induced in a body as a result of changes in temperature.