P6 - Matter Flashcards
Change in thermal energy
The prodcut of the mass, specific heat capacity and temperature change of a susbstance
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 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
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 syste
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
Specific latent heat of vaporisation
The amount of energy needed to change the state of one kilogram of a substance from liquid state to vapour state, whilst held at constant temperature
