particle model of matter definitions Flashcards
change in thermal energy
The product of the mass, specific heat capacity and
temperature change of a substance.
chemical changes
changes to the chemical structure of a substance. The
substance does not usually restore its original properties when the changes are
reversed.
condensation
The changing from vapour state to a liquid state, when a
substance is cooled.
density
The mass per unit volume of an object.
evaporation
The changing from liquid state to a vapour state, when a substance
is heated.
freezing
The changing from a liquid state to a solid state, when a substance is
cooled.
gas temperature
The temperature of a gas is directly proportional to the
average kinetic energy of its molecules.
internal energy
The energy stored by the atoms and molecules that make up a
system. It is equal to the sum of the total kinetic and potential energies of the particles in the system
latent heat
The energy required for a substance to change state
melting
The changing from solid state to liquid state, when a substance is
heated.
pascals
The unit of pressure, equal to a force of one Newton acting
perpendicular to an area of one metre squared.
physical changes
Changes to the physical properties of a substance which can
be reversed. Changes of state are physical changes since substances can restore
their original properties when the changes are reversed.
pressure
The force acting perpendicular to a surface, per unit area.
specific heat capacity
The amount of energy needed to increase the
temperature of one kilogram of a given substance by one degree Celsius.
specific latent heat of fusion
The amount of energy needed to change the state of one kilogram of a substance from solid state to liquid state, whilst held at constant temperature
