Group 7

• Group 7 are also known as halogens
• Why do group 7 elements react similarly?

  All have 7 outer electrons (react by gaining 1 electron)
• What type of compounds do they form with metals?

  Ionic lattices
• What type of compounds do they form with other non-metals?

  Covalent molecules
• How do the group 7 elements exist on their own?

  As diatomic moleciules
• What happens to properties down group 7 and why?

  • Relative molecular mass increases & gains more electrons / shells
  • The melting and boiling point increases due to stronger molecular intermolecular forces between molecules
  • Reactivity decreases due to more electron shells (greater distance between nucleus and outer shell), weaker attraction for extra selection. Electrons are more difficult to gain.
• What is a halogen?


  it is an element in group 7
• What is a halide?


  The negative ion formed by a group 7 element by gaining an outer electron
• What type of reaction occurs when a more reactive halogen reacts with a less reactive halide?

  Displacement