#3.1.2a
the outer shell s2 electron configuration and the loss of these electrons in redox reactions to form 2+ ions
#3.1.2b
the relative reactivities of the Group 2 elements Mg → Ba shown by their redox reactions with:
(i) oxygen
(ii) water
(iii) dilute acids
Reactions with acids will be limited to those producing a salt and hydrogen.
#3.1.2c
the trend in reactivity in terms of the first and second ionisation energies of Group 2 elements down the group (see also 3.1.1c)
Definition of second ionisation energy is not required, but learners should be able to write an equation for the change involved.
#3.1.2d
the action of water on Group 2 oxides and the approximate pH of any resulting solutions, including the trend of increasing alkalinity
#3.1.2e
uses of some Group 2 compounds as bases, including equations, for example (but not limited to):
(i) Ca(OH)2 in agriculture to neutralise acid soils
(ii) Mg(OH)2 and CaCO3 as ‘antacids’ in treating indigestion.