group 2

• Group II metals


  Lose two electrons to form 2+ ions when they react in order to achieve a full outer shell
• Atomic radius of group II metals

  • Increases down the group due to additional electron shells
• Reactivity of group II metals

  Increases down the group due to increased electron shielding making the outer electrons easier to lose
• First ionisation energy of group II metals


  Decreases down the group due to a greater atomic radius and increased amounts of shielding
• Melting point of group II elements


  Decreases down the group as the larger ions within the metallic structure have weaker attractive forces acting over a greater distance
• Reaction of group II metals with water

  1. Metal is oxidised

  2. Metal hydroxide and hydrogen are produced

  3. Metal hydroxide forms an alkaline solution
• Solubility of group II hydroxides

  Increases down the group, with magnesium hydroxide being the least soluble and barium hydroxide the most soluble

  
• Uses of group II hydroxides

  • Magnesium hydroxide used as an antacid and to neutralise acidic soils

  
• Solubility of group II sulfates

  Decreases down the group, with magnesium sulfate being the most soluble and barium sulfate the least soluble
• Uses of barium sulfate


  • Used in medicine as barium meals, a form of medical tracer that allows internal tissues and organs to be imaged
  • Barium sulfate is insoluble so cannot be absorbed into the bloodstream, making it safe to use
• Use of barium chloride

  • Used as a test for sulfate ions, reacting to form a white precipitate of barium sulfate

  
• Magnesium used in the extraction of titanium


  Displacement reaction with titanium chloride

  
• Calcium oxide used in flue gas removal


  Reacts with sulfur dioxide to form calcium sulfite and water, removing sulfur dioxide from factory pollutants