1)Sodium is a very reactive metal,therefore sodium metal react violently even with cold water. Strontium and barium have reactivities similar to that of lithium. Calcium, for example, reacts fairly vigorously and exothermically with cold water. Solution: Let us first write down the chemical formulas. The intensity of reaction of a metal with water depends on its chemical reactivity. Some water-reactive substances are also pyrophoric, like organometallics and sulfuric acid, and should be kept away from moisture. Notable examples include alkali metals, sodium through caesium, and alkaline earth metals, magnesium through barium.. If the reactants are a metal and water, the products would be a base and hydrogen gas (don't forget the subscript 2 for diatomic). Solid sodium metal reacts with water, giving a solution of sodium hydroxide and releasing hydrogen gas. Write a balanced equation for the reaction using complete formulas for the compounds with phase labels. These metals react with cold water with increasing vigor to give the metal hydroxide and hydrogen. Some metals react vigorously even with cold water,some react with hot water,some metals react with steam whereas some metals do not react even with steam. Reaction of zinc metal with water: Zinc metal produces zinc oxide and hydrogen gas when steam is passed over it. $$\ce{2Li(s) + 2H2O(l) -> 2LiOH(aq) + H2(g)}$$ Also remember that if the metal that displaces the Hydrogen has a charge, for instance Iron (II), although that wouldn't be realistic, the reactants would become $\ce{Fe(OH)2 + H2}$. Zn + H 2 O ⇨ ZnO + H 2. Iron forms rust (iron oxide) when reacts with moisture present in atmosphere. Sodium and potassium metal are stored under kerosene oil to prevent their reaction with the oxygen,moisture and carbon dioxide of air.They are so reactive that they react vigorously with oxygen.They catch fire and start burning when kept open in the air. Water-reactive substances are those that spontaneously undergo a chemical reaction with water, as they are highly reducing in nature. Reaction of Iron with water: Reaction of iron with cold water is very slow and come into notice after a long time. Zinc does not react with cold water. Metal oxides are basic in nature.They turn red litmus to blue.