Group 7: Atomic structure and the periodic table: Chemistry: GCSE (9:1)

• Name of Group 7 elements

  The halogens

  
• Group 7 elements have similar chemical properties

  because they all have 7 outer shell electrons

  
• Diatomic molecule


  A molecule consisting of two atoms

  
• Chemical structure of group 7

  diatomic molecules

  
• Pattern in melting points and boiling points down group 7

  melting and boiling points decrease
• Pattern of reactivity down the halogens

  they get less reactive
• Reason for patterns in reactivity

  larger atomic radius, more shielding, less nuclear attraction, harder to gain a reaction
• Group 7 elements react by

  gaining 1 electron

  
• Displacement reaction

  A reaction in which a more reactive element replaces a similar element in a compound

  
• Potassium bromide + Chlorine -->

  Potassium chloride + Bromine

  
• Sodium chloride + Bromine -->


  No reaction
• Sodium iodide + Bromine -->


  Sodium bromide + Iodine