chemistry: group 2

• melting point

  • decreases
  • atomic radius increases
  • metallic bonding decreases
  • distance increases
  • so electrostatic forces of attraction between positive ions and delocalised electrons decreases
• reactivity of group 2 metals increases down the group
• thermal stability increases down the group
• thermal stability of group 2 metal nitrates + carbonates

  • increases
  • group 2 ion has lower charged density as we move down
  • so less distortion of the carbonate/nitrate ion
  • less distortion means more stable
  • higher temperatures required to decompose the carbonate/nitrate ion
• group 2 metals burn in O2 to form metal oxides
• • calcium burns in oxygen with a brick red flame
  • magnesium burns in oxygen with an intense white flame
  • strontium burns with a white / crimson flame
  • barium burns with an apple green flame
• group 2 hydroxides solubility increases down the group ( beriliyum is insoluble and is amphoteric)
• oxides dissolve in water to form hydroxides
• group 2 oxides react with acids to form salt and water
• solubility of group 2 sulfates decreases down the group
• magnesium will react with steam to produce magnesium oxide and hydrogen gas
• magnesium will react with cold water to produce magnesium hydroxide and hydrogen gas
• group 2 metals react with water to give hydroxides and hydrogen gas (except beriliyum)
• when calcium react with water, produces calcium hydroxide

  • Ca sinks
  • vigorous reaction
  • dissolves to give alkaline solution
• reactivity of group 2 metals increases

  • atomic radius increases
  • sea of delocalised electrons are further away from the nucleus
  • more shielding effect
  • weaker force of attraction between cations and sea of delocalised electrons