describe the difference in reactivity between Ba and Sr
Ba is more reactive as it has more shielding and more shells therefore the nuclear attraction is weaker making it easier to lose an electron which outweigh the nuclear charge of Sr
does the reactivity increase or decrease down the group
increases
group 2 elements are known as alkali earth metals
in group 2 metals the reactivity increases as it goes down the group as the atomic radius increases, more shielding and the nuclear attraction decreases so its easier to lose an electron
group 2 oxides - XO +H2O --> X(OH)2 (alkali)
the Ph of the hydroxides depends on the solubility of the hydroxides (increases as it goes down the group)
uses of group 2 compounds
CA(OH)2 - agriculture to neutralise acidic soils
Mg(OH)2 and CaCO3 as antacids in treating indigestion
