As you go down the activity series the reaction between water and metal becomes slow. The first metals like sodium and potassium react very violently with water producing the respective alkali and hydrogen. Then comes calcium which reacts a little less violently with water. Then there is magnesium which reacts with either hot water or steam. Then the rest of the metals like zinc aluminium iron react only with steam. Lead does not react with water and the metals below hydrogen do not react with water