3.1.2 group two

Group 2 + water =

Metal hydroxide + hydrogen

How does reactivity for Group 2 change down the group?

They get more reactive because the outermost electrons are further away from the nucleus

Group 2 + oxygen =

Metal oxide - often a white solid

Group 2 oxides and hydroxides are bases so they:

Form alkaline solutions in water

Neutralise acids

Group 2 oxide + water:

Dissolves into metal ion + hydroxide ion, which is a strongly alkaline solution

How do the alkaline solutions change as you go down group 2?

They become stronger, as the hydroxides become more soluble

Group 2 hydroxides ...

...become more soluble as you go down the group

Group 2 carbonates ...

...become less soluble as you go down the group

Thermal decomposition of group 2 carbonates produces ...

... group 2 oxide + carbon dioxide

Thermal stability of carbonates increases down the group because:

Small cations at the top of group 2 as smaller atoms

So, higher charge density

Distorts the carbonate ion more

Further down the group means larger cation means less distortion so more stable