Topic 3: Particle Model of Matter 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.
