- The Group 2 metals need to lose two electrons to obtain a full octet of electrons, and thus these would have a +2 charge.
- These metals have got low densities, are ductile and are silvery grey in colour.
- Most group 2 metals give a coloured flame during a flame test.
- The reactivity of the metals increases down a group, due to the increase of the number of shells, making the electrons further away from the nucleus, and therefore easier to be lost.
The reactions that are going to be analysed for group 2 metals are reactions with Oxygen, water and acids
Oxygen
2Ca + O2 → 2CaO
This is a simple reaction, where the metal reacts with Oxygen to forms a metal oxide. There may be some coloured flames due to the tendency of group 2 metals to produce a coloured flame.
Water
In water there are two sets of reaction. All of the elements lower then Calcium and including Calcium in the periodic table would react with water instantly, even at room temperature with the following reaction:
Ca + 2H2O → Ca(OH)2 + H2
If Magnesium is used it must be noted that no reaction would take place at room temperature and in order for this reaction to take place steam must be used. The reaction would be a two-step reaction:
Mg + H2O(g) → MgO + H2
MgO + H2O → Mg(OH)2
In this reaction the oxide is formed when the metal reacts with water and then a normal reaction, i.e. the oxide with water presumes.
Acids
Mg + 2HCl → MgCl2 + H2
This is a simple displacement reaction where Mg takes place of the H+ due to the Mg being higher in the reactivity series.