Most metals react with water to form metal hydroxides and hydrogen gas. A few metals, such as sodium and potassium, react vigorously and can even ignite or explode when they come in contact with water. Other metals, such as copper and silver, do not react with water.
When sodium reacts with water, it forms sodium hydroxide (NaOH) and hydrogen gas (H2).
The chemical equation is:
2 Na (s) + 2 H2O (l) → 2 NaOH (aq) + H2 (g)