Halogens

• Halogens

  • Group 17 elements
  • non metals that exist as diatomic molecules
  • low melting and boiling point since weak intermolecular forces of attraction between molecules requires small amount of energy to overcome
  • react with metals to form slats
• Halogens Trends

  • melting point and boiling point increase down the group
  • colour intensity increases down the group
  • reactivity decreases down the group as atomic size increases. SInce valence electrons shell is further away from nucleus, it becomes more difficult for the nucleus to attract one more electron, so atoms gain one electron less easily
  • oxidising power decreases down the group
• Displacement reaction

  • halogens undergo displacement reactions
  • a more reactive halogen displaces the less reactive halogen form its halide solution
  • a displacement reaction is a redox reaction