Physical Properties-

• Halogens exist as simple molecules
• Each molecule contains two halogen atoms joined by a single covalent bond
• Chlorine:

  • Colour: greenish-yellow
  • Physical state: gas at room temperature
• Bromine:

  • Colour: red-brown
  • Physical state: liquid at room temperature
• Iodine:

  • Colour: purple
  • Physical state: solid at room temperature
• Melting points and boiling points of the halogens increase going down group 7
• This is because, going down group 7:

  • The molecules become larger
  • The intermolecular forces become stronger
  • More energy is needed to overcome these forces