Liquid nitrogen has a temperature between about minus 196 degrees Celsius and about minus 210 degrees Celsius.

Liquid nitrogen is converted from nitrogen, which becomes liquid when the temperature drops to around minus 196 degrees Celsius at standard atmospheric pressure, and liquid nitrogen becomes snow-like solid nitrogen if the temperature continues to drop to around minus 210 degrees Celsius. Liquid nitrogen is colorless, odorless, non-flammable and inert, and is generally used as a refrigerant in life.

Liquid nitrogen is an inert, colorless, odorless, non-corrosive, non-flammable, very low-temperature liquid that absorbs a lot of heat when it vaporizes contact causes frostbite. Nitrogen makes up most of the atmosphere. At atmospheric pressure, the boiling point of nitrogen is -196.56°C. One cubic meter of liquid nitrogen can expand to 696 cubic meters of pure gaseous nitrogen (21°C). If pressurized, liquid nitrogen can be obtained at even higher temperatures.

In industry, liquid nitrogen is obtained by fractionating air. The air is first purified, then liquefied under pressure and cooling, and separated by the different boiling points of the components in the air. Direct contact with the human skin liquid nitrogen instantly is not a problem, more than 2 seconds will be frostbite and irreversible.