Group 7 (halogens) – chlorine, bromine and iodine

• Anagrams


  • Halogen
  • Halide
  • Alkali Metals
  • Periodic table
  • Bromine
  • Diatomic
  • OMg
• Halogen


  An element that belongs to group 7 of the periodic table
• Halide


  Name of a halogen when it has reacted with another element and gained a full outer electron shell
• Did you hear oxygen and magnesium got together….OMg!
• Group 7 - The Halogens


  • Reactivity DECREASES as you go down the group
  • Fluorine and chlorine are gases at room temperature, bromine is a liquid and Iodine is a solid
  • They exist as diatomic molecules (so that they both have a full outer shell)
• Lesson objectives


  1. Describe how the Group 7 elements behave

  2. Describe how the properties of the Group 7 elements change going down the group
• Halogens


  Reactive, coloured poisonous, non-metal elements from group 7
• Appearance


  • Chlorine - Green Gas
  • Bromine - Red-brown Liquid
  • Iodine - Purple solid
• Melting / Boiling Point


  • Chlorine
  • Bromine
  • Iodine
• Uses

  • Chlorine - Disinfectant
  • Bromine
  • Iodine - Treat drinking water
• Fluorine, F2, is a pale yellow gas at room temperature.
• Chlorine, Cl2, is a pale green gas at room temperature.
• Bromine, Br2, is a dark red liquid at room temperature. It is the only liquid non-metal.
• Bromine is volatile and readily forms a dark red vapour.
• Iodine, I2, forms shiny black crystals at room temperature.
• When warmed, iodine crystals sublime (turn directly to a gas), forming a purple vapour.
• States of halogens


  • Gas
  • Gas
  • Liquid
  • Solid
• Group 7 – The Halogens