2.2 group 2 metals

• Group 2 elements form plus two ions when they react
• Electron configuration of group 2 elements

  Ends in S2
• Atomic radius of group 2 elements

  • Increases as you go down the group
• First ionization energy of group 2 elements

  • Decreases as you go down the group
• Increase in number of protons as you go down group 2


  Shielding effect overrides this increase in positive charge
• Melting points of group 2 elements

  • Generally decrease as you go down the group
• Reaction of group 2 elements with water

  Form metal hydroxides and hydrogen gas
• Barium does not react with water
• Magnesium reacts slowly with cold water but more vigorously with steam, producing magnesium oxide instead of a hydroxide
• Solubility of group 2 hydroxides and sulfates

  Opposite trends as you go down the group
• Test for sulfates


  Add hydrochloric acid to remove carbonates, then add barium chloride to form a white precipitate of barium sulfate
• Neutralization using group 2 compounds

  Used to neutralize acidic soils and excess stomach acid
• Barium meals


  • Barium sulfate used to help identify problems with the digestive tract
• Extraction of titanium


  Titanium ore converted to titanium chloride, then reduced using magnesium to produce pure titanium
• Removal of sulfur dioxide emissions


  Spray calcium carbonate or oxide solution onto the gas to form calcium sulfate, which can be sold