AQA P6 Molecules and matter

P6

boiling point

temperature at which a pure substance boils or condenses

melting point

temperature at which a substance melts or solidifies

Boyle's Law

for a fixed mass of gas at constant temperature, its pressure multiplied by its volume is constant

density

mass per unit volume of a substance

freezing point

the temperature at which a pure substance freezes

internal energy

the energy of the particles of a substance due to their individual motion and positions

latent heat

the energy transferred to or from a substance when it changes its state

melting point

temperature at which a pure substance melts or freezes (solidifies)

physical change

a change in which no new substances are produced

pressure

force per unit cross-sectional area for a force acting on a surface at right angles to the surface. The unit of pressure is the pascal (Pa) or newton per square metre (N/m2). p = F/A

specific latent heat of fusion Lf

energy needed to melt 1 kg of a substance with no change of temperature

specific latent heat of vaporisation Lv

energy needed to boil away 1 kg of a substance with no change of temperature