models

• uses & disadvantages of dot and cross

  Dot and cross

  • useful for showing how compounds are formed (ionic)
  • useful for showing which atoms electrons come from (covalent)
  • doesn't show structure, arrangement or relative sizes
• uses & disadvantages ball and stick

  Ball and stick

  • shows the regular pattern and arrangement of ions in the lattice
  • may show relative sizes
  • however, they suggest that there are gaps in between ions when in reality there aren't
• uses & disadvantages of 3D

  3D models

  • show relative sizes of ions
  • shows regular pattern of ions
  • however, they only let you see the outer layer of the compound
• pros and cons of displayed formula

  great for showing how atoms bond in large molecules 

  does not show 3D structure

  or which atoms electrons come from in covalent bonds