Solids expands and contracts the least followed by liquid then gas.
When cooled, solids, liqiuds and gases contract and decrease in volume.
When heated, solids, liquids and gases expand and increase in volume
Effects on everyday life
Problems
Laboratory glassware cracking when heated due to uneven expansion
Telephone and electrical wires snapping on cold days due to contraction
MRT and railway tracks wrap on hot days due to expansion
Bridges cracking on hot days due to expansion
Tiled and concrete pavements cracking on hot days due to expansion
Water pipes cracking or bursting on hot days due to expansion
Solutions
Water pipes are built with expansion bends to allow space for espansion
Laboratory glassware is made of Pyrex glass which expands very little when heated
Telephone and electrical wires are hung loosely to allow space for contraction
Bridges are built with rollers on one side to allow expansion
Pavements and tiles have expansion gaps that allows space for expansion
Transfer of thermal energy
Conduction
Conduction is the process of thermal energy transfer through a medium from one particle to another
All matters are conductors of thermal energy
Solids are generally better
conductors of thermal energy as
compared to liquid and gas
Convection
Convection is the
process in which
thermal energy is
transmitted by the
movement of liquid or
gas. It cannot occur in
solid
Occurs through a convection current
Radiation
Radiation is the
process in which
thermal energy is
transferred by
electromagnetic waves.
It does not require a
medium, thus it can
occur in a vacuum
Factors that affect rate of radiation
Nature of the surface of the body; colour, reflectivity and texture. Surfaces
which are dark in colour, matte and rough are better radiators of heat compare
to surfaces which are light in colour, shiny and smooth