physics-particles model of matter

change in thermal energy

the product of the mass ,specific heat capacity and temputure 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

evapouration

the changing from liquid state to a vapour state when a substance is heated

freezing

the hanging from a liquid to solid state when a substance is cooled

gas temperature

the temperature of a gas is directly proportional to the average kinetic energy of its molecule

internal energy

he 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 sate to liquid state when a substance is heated.