Group 2

• Trends in properties:

  atomic radius increases

   

  • Outer electrons are further from the nucleus + are easier to remove
  • First and second ionisation energy + electronegativity decreases down the group

   

  Reactivity increases down the group
• Trends in physical properties

   

  higher melting and boiling point than Group 1

   

  stronger metallic bonding (lower than transition metals)

   

  like all metals they conduct heat and electricity
• Melting point

   

  partial pattern related to melting point

   

  (ignoring magnesium) overall trend shows a decreasing melting point

   

  magnesium is an exception as it has a different crystalline structure
• Boiling point

   

  there is not pattern related to boiling point within group 2 metals

   

   
• Trends in chemical properties

   

  solubility of sulphates decrease down the group

   

  Solubility of hydroxides increase down the group
• solubility in water of some group 2 sulfates:

   

  decreases as the radius of the metal ion increases
• nitrates and carbonate become more thermally stable as you descend the group

   

  need more energy to decompose the compounds

   

  examples -

  A) 2MO + 4NO2 + 02

  B) MO + CO2

  
• Thermal stability down group 1

  Nitrates and carbonates become more thermally stable

  As you descend the group

   

  need energy to decompose the compounds
• Na and K (group 1) do not have any reaction to thermal stability as the temperature required is too high