• diatomic molecules
• low melting point and boiling point (diatomic molecules - simple molecular structure with weak dispersion force between molecules)
• coloured
• non-conductor of electricity
• a more reactive halogen displaces a less reactive halogen from the salt of a less reactive halogen
  • [more reactive halogen] is more reactive than [less reactive halogen]. Hence, [more reactive halogen] displaces [less reactive halogen] from [salt]
    • Bromine is more reactive than Iodine. Hence, Bromine displaces iodine from KI.