- Form ionic compounds in they have an oxidation state of 2
- Form ionic compounds with a higher Lattice energy when compared to the alkali metal compounds.
- Less thermally stable then group 1
- Ionisation energy decreases down the group
- Higher densities then group 1
- Grey in colour
Group 2 metals react in air to form the simple oxide, except for barium, which produces the superoxide.
2Be (s) + O2(g) à 2BeO(s)
2Mg (s) + O2(g) à 2MgO(s)
2Ca (s) + O2(g) à 2CaO(s)
Ba (s) + O2(g) à BeO2(s)
The reactivity of group 2 compounds with water increases down the group.
Beryllium does not react with water.
Magnesium reacts with steam to produce the oxide and Hydrogen
Mg + H2O(g) à MgO + H2
Calcium and Barium react with water to produce the hydroxide and Hydrogen.
Ca + 2H2O(l) à Ca(OH)2 + 2H2
Solubility of hydroxides increase down the group. Magnesium hydroxide is insoluble while barium hydroxide is completely soluble.
Preparation of Magnesium hydroxide is obtained by a precipitation reaction.
All group 2 hydroxides break down when heated to give the oxide and water.
Mg(OH)2 à MgO + H2O
These are prepared by precipitation reactions with the solubility decreasing down the group.
All carbonates are thermally unstable to give CO2 and the oxide.
CaCO3 à CaO + CO2
All nitrates break down to produce the oxide, nitrogen dioxide and oxygen.
2Mg(NO3)2 à 2MgO + 4NO2 + O2