states of matter

• solid


  strong forces of attracitoon between particls - close together in fixed position to attain very regular lattice arrangement

  particles dont move from their position - definite shape and volume

  particles vibrate in their position - heat = more vibrations = slight expansion
• liquid


  weak force of attraction

  randomly arranged

  free to move past each other but tend to stick closely together

  definite volume but dont keep a definite shape will flow to bottom of container

  constantly moving with random motion

  hotter = faster = expand
• gas


  force of attraction between particles is very weak

  free to move and are far apart

  particles travel in straight lines

  dont keep definite shape or volume - always fill container

  move constantly with random motion

  hotter = faster = expand or higher pressure
• why is particle theory not great


  particles arent solid or inelastic and not spheres = atoms ions or molecules

  model doesnt show forces of attraction between particles = no way of knowing how strong they are
• s

  solid
• l

  liquid
• aq


  aqueous
• g

  gas
• how to predict the state of a substance


  temperature below melting point of a substance it'll be solid

  if above boiling pint its a gas

  if its in-between both points its liquid
• physical changes are


  reversible
• nanoparticles


  Very very small particles (1-100 nanometers in size)
• coarse particles


  PM10

  diameter between 2500nm and 10000nm

  also called dust
• fine particles


  PM2.5

  diameter between 100nm and 2500nm
• what do nanoparticles have


  large surface area to volume ratio

  less nanoparticles = catalyst
• what can nanoparticles be used for


  new catalysts

  nanomedicine

  electric circuits - conduct electric

  silver nanoparticles have antibacterial properties - be added to polymer fibres = surgical masks and wound dressings or deodorant

  cosmetics