physics p6 molecules and matter

mass

amount of matter in something, measured in kg

volume

amount of space something takes up. measured in m squared

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volume of an irregular object can be found using a displacement can

density

mass per unit volume, measured in kg/m squared

floating

an object with a lower density than the liquid will float

sinking

an object with a higher density than the liquid will sink

evaporation

happens at any temp

sublimation

solid turns straight into gas

solid

particles held together in fixed positions by strong forces, least energetic

liquid

particles move at random but are in contact with each other. medium energy

gas

particles move randomly and are far apart from each other. weak forces of attraction, most energetic

melting point

temperature where solid turns to liquid, same as freexing point

boiling point

temperature where liquid turns to gas, same as condensation point

latent heat

energy transferred when a substance changes state but temperature doesnt change

specific latent heat of fusion

energy needed to melt 1kg of solid into liquid

specific latent heat of vaporisation

energy needed to boil 1kg of liquid into gas

At state changes

temperature and kinetic energy of particles stays constant, internal energy increases due to an increase of potential energy as particles move further apart

Heating and cooling curves

gas pressure

caused by particles hitting surfaces. increases when temperature increases