Chapter 1 Flashcards
Solids
- 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
Liquids
- 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)
Gasses
- 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)
liquid to solid
Freezing
Solid to liquid
Melting
Liquid to gas
Evaporating or boiling
Gas to liquid
Condensing
Gas to solid
Deposition
Solid to gas
Sublimation
Boiling
When liquid heated to its boiling point -> gradually turns into gas
Evaporating
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
Temperature during a change of state
It doesn’t change -> stays constant
Heating
Energy put in absorbed to overcome forces between particles
Cooling (condensing + freezing)
Thermal energy released from formation of new forces between particles stops temperature from falling
Sloped bits (heating and cooling curves)
Temperature of substance increasing
Flat bits (heating and cooling curves)
Substance changing state
Volume of gasses: pressure
Increasing pressure: partciles pushed closer together -> volume decreases
Decreasing pressure: particles can drift further apart -> volume increases
Volume of gasses: temperature
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
Diffusion
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)
Rate of diffusion of gas
Depends on its molecular mass -> small, light gas molecules move faster than longer, heavy gas particles and so will diffuse faster
