GROUP 2

• Atomic radius increases down the group:

  • extra electron shells
• First ionisation energy decreases down the group:

  • extra electron shells (shielding)
  • outer electrons further from nucleus
• reactivity increases down the group (as first ionisation energy decreases- shielding/ electrons further away).... easier to loose electrons
• melting points decrease down the group

  • metal ions get bigger but number of delocalised electrons stays the same.
  • larger ionic radius , further away delocalised electrons... less attraction to nucleus...less energy required to break bonds
• Group 2 metals react more readily with water down the group because the ionisation energies decrease
• Group 2 hydroxides increase in solubility down the group (Mg-Ba)
• Mg(OH)2 said to be sparingly soluble
• Group 2 sulphates decrease in solubility down the group (Mg-Ba)
• Barium sulphate= insoluble
• observations of magnesium with steam:

  • white solid/power
  • bright white light

  Mg+H2O=MgO+H2