Chapter 1

• Closed together in fixed positions to form a regular lattice arrangement -> strong forces of attraction between particles • Don’t move from their positions -> definite shape and volume • Vibrate in the spot -> the hotter the solid becomes = partciles vibrate more (causing solids to expand slightly when heated

• Randomly arranged and free to move past each other but tend to stick closely together -> weak forces of attraction between particles • Flow to fill container -> definite volume but jot shape • Constantly moving in random motion -> the hotter the liquid gets= the faster the particles move (casuing liquids ro expand slightly when heated)

• Far apart and free to move travelling in straight lines -> very weak forces of attraction between particles • Move to fill container -> no definite shape of volume • Constanly moving with random motion -> the hotter the gas gets= particles move faster (gas either expand when heated OR pressure increases)

Freezing

Melting

Evaporating or boiling

Condensing

Deposition

Sublimation

When liquid heated to its boiling point -> gradually turns into gas

Can happen at any temperatures below a liquids boiling point -> more energetic particles near the surface of the liquid can escape to form a vapour

It doesn’t change -> stays constant

Energy put in absorbed to overcome forces between particles

Thermal energy released from formation of new forces between particles stops temperature from falling

Temperature of substance increasing

Substance changing state

Increasing pressure: partciles pushed closer together -> volume decreases Decreasing pressure: particles can drift further apart -> volume increases

Increasing temperature: particles have more kinetic energy + move faster and so spread out and occupy more space -> volume increases Decreasing temperature: particles have less kinetic energy + move less and don’t spread out -> volume decreases

Net movement of particles from an area of high concentration to low concentration -> due to random movement of particles in liquids and gasses (no energy needed)

Depends on its molecular mass -> small, light gas molecules move faster than longer, heavy gas particles and so will diffuse faster