Which of the following is a non-metal that can be stored in the water?

Phosphorous

The correct answer is option 3. Phosphorus.

Phosphorus is a non-metal element that exists in several allotropic forms, the most common of which are white phosphorus, red phosphorus, and black phosphorus. White phosphorus is highly reactive and can spontaneously ignite in air, leading to combustion. To prevent this reaction, white phosphorus is typically stored underwater.

When white phosphorus is submerged in water, it is isolated from the oxygen in the air, which helps prevent its oxidation and combustion. Water acts as a barrier, effectively sealing the phosphorus from the surrounding air. This prevents the white phosphorus from coming into contact with oxygen, thereby reducing the risk of spontaneous ignition.

In addition to preventing combustion, storing white phosphorus underwater also helps to maintain its stability and prolong its shelf life. This is important for handling and transportation purposes, as well as for ensuring safety in storage facilities.

Overall, storing white phosphorus in water is a common practice to mitigate the risk of accidental ignition and to maintain its stability until it is ready for use in various applications, such as in the production of phosphoric acid, fertilizers, and certain types of chemicals.