Describe the reasons why the rates of strontium and barium with water is different

Barium reacts quicker with water than strontium as it has a lower first ionisation energy than strontium as barium has a larger atomic radius and so their is more shielding for the outer electrons. although barium has a greater nuclear charge than strontium which would decrease the reaction rate, this effect is outweighed by the other two factors mentioned. Barium therefore reacts faster with water than with strontium