Sodium Metal Vs. Water experiment 💥 Why does sodium explode in water? When sodium metal comes into contact with water, a highly exothermic reaction occurs. This reaction happens because sodium reacts vigorously with water, producing hydrogen gas and sodium hydroxide. The heat generated from this reaction ignites the hydrogen gas, resulting in a fiery explosion. This reaction is so vigorous because sodium is highly reactive, especially with water, due to its low ionization energy and affinity fo