Halogens

• Halogen states and colours at RTP:

  • Fluorine- Yellow gas
  • Chlorine- Green gas
  • Bromine- Red liquid
  • Iodine- Black solid
• What are the properties of halogens?

  Poisonous

  Diatomic; form halide ions in displacement reaction

  Do not conduct electricity

  Brittle and crumbly when solid
• Patterns of Halogens:

  • Down the group; size, mass and density increase
  • Down the group, color darkens
  • melting point increases down the group
• Reactivity decreases down the halogen group,

  because it has to gain an electron,

  so the closer the electron is to the positive nucleus the more easily it will be gained,

  so atoms with fewer shells will react more easily.