I believe that you think to alkali metals (ex. sodium).
Sodium is a metal that reacts violently with water, sometimes bursting into flames. The reaction produces sodium hydroxide and hydrogen gas.
The substance is likely sodium, a highly reactive metal that reacts violently with water to produce sodium hydroxide and hydrogen gas. The heat generated from this reaction can ignite the hydrogen gas, resulting in flames. Additionally, the reaction is so exothermic that it can be explosive.
That phenomenon is known as a reactive metal-water reaction. Certain metals, such as sodium and potassium, react violently with water, producing heat and hydrogen gas that can ignite. This reaction is highly exothermic and can lead to the metal bursting into flames.
Potassium is the only metal (alkali metal) where a flame is present. Lithium and sodium fizz but there is no flame. Caesium, francium and rubidium all explode on contact with water.
Throw water on it. The logical answer.
A soft, light weight metal called sodium, which we never see. It bursts into flames in air and can even burn under water.
A metal oxide reacts with water to produce a metal hydroxide.
Potassium is the metal that reacts most vigorously with water at 25C.
The metal that reacts slowly with cold water to form a hydroxide is magnesium. When magnesium reacts with water, it forms magnesium hydroxide and hydrogen gas.
When an alkali metal reacts with water, it produces an alkali metal hydroxide and hydrogen gas. This is a highly exothermic reaction, with the alkali metal displacing hydrogen from the water molecule.
Zinc is a grey metal that can react with water, although it does so slowly. When zinc reacts with water, it produces zinc hydroxide and hydrogen gas.
A corresponding metal salt and water are produced.