Describe the reactions, if any, of: (a) potassium, sodium and calcium with cold water (b) magnesium with steam (c) magnesium, zinc, iron, copper, silver and gold with dilute hydrochloric acid and explain these reactions in terms of the position of the metals in the reactivity series

Describe the neutralisation reaction between an acid and an alkali to produce water, ( H^+(aq) + OH^- (aq) ightarrow H_2O (l) )