Nitrogen is chemically inactive and is an inert gas. It is difficult to react with other substances at room temperature. It plays an important role in both industrial fields and daily life.

Nitrogen has the following wide uses.

(1) Nitrogen inflating tires, inflating tires with nitrogen can reduce the oxidation and corrosion of tires by oxygen and moisture in the air, reduce tire wear, reduce the probability of tire blowouts, and improve driving safety.

(2) In industry, nitrogen is an important raw material for synthesizing ammonia, preparing nitric acid and fertilizers.

(3) The chemical properties of nitrogen are very inactive under normal conditions, so it is often used as a protective gas. Nitrogen is used to protect the metal from oxidation when welding the metal.

(4) Filling the light bulb with nitrogen can prevent the oxidation of the tungsten wire and slow down the volatilization rate of the tungsten wire, thus prolonging the service life of the light bulb.

(5) In museums, some precious and rare paintings and scrolls are often kept in nitrogen-filled cylinders, which can make borers suffocate in nitrogen.

(6) Nitrogen is also commonly used as a protective gas for foods such as grain, canned food, and fruit. Nitrogen is used to make the grain in a state of dormancy and hypoxia, and its metabolism is slow, which can achieve good insect-proof, mildew-proof and anti-deterioration effects. The grain is not polluted, the management is relatively simple, and the cost is not high, so it has developed rapidly in recent years. At present, countries such as Japan and Italy have entered the stage of small-scale production experiments. In recent years, many areas in my country have also used nitrogen to preserve grain, which is called "vacuum nitrogen-filled grain storage", and can also be used to preserve agricultural and sideline products such as fruits.

(7) In medicine, liquid nitrogen is often used as a cryogen, and operations are performed under cryogenic anesthesia. The use of liquid nitrogen to cool the scalpel becomes a "cold knife". Doctors use "cold knives" to operate with less or no bleeding, and patients can recover faster after surgery. The use of liquid nitrogen to treat skin diseases for patients is also very effective. This is because the vaporization temperature of liquid nitrogen is -195.8C. Therefore, it is often easy to make the skin necrosis and fall off when used to treat superficial skin diseases. In the past, dermatologists often used "dry ice" to treat hemangiomas. Although the intention was the same, the coldness was far less than that of liquid nitrogen. The "artificial pneumothorax" for the treatment of pulmonary tuberculosis is also to inject nitrogen (or air) into the chest cavity of the pulmonary tuberculosis patient, compress the lobe of the lung with lesions, and make it rest.

(8) In the high-tech field, liquid nitrogen is often used to create a low-temperature environment. For example, some superconducting materials obtain superconducting properties at low temperature after being treated with liquid nitrogen.