The principal component of the Earth’s atmosphere (78.084 percent by volume), nitrogen gas is colorless, odorless, tasteless, and relatively inert. Its density at 32 degrees Fahrenheit (0 degrees C) and one atmosphere of pressure (101.325 kPa) is 0.07807 lb/cubic foot (0.0012506 grams/cubic centimeter).

The boiling point of nitrogen gas at one atmosphere of pressure (101.325 kPa) is -320.4 degrees F (-195.8 degrees C).

Nitrogen gas does not normally react with most substances and does not support combustion.

Nitrogen gas has many industrial uses because of its stability. Since it will not react with most compounds under normal conditions, it is used as a preservative to prevent oxidation. When chilled to its liquid state, nitrogen is widely used in medical, chemical, and manufacturing industries as a refrigerant.

As an important element required in the synthesis of many organic compounds, nitrogen serves as the limiting nutrient in many ecosystems. Most organisms lack the ability to utilize nitrogen gas as a source of nitrogen; however, through a process known as nitrogen fixation, some agriculturally important bacteria synthesize nitrogen molecules from atmospheric nitrogen gas.

When a person breathes air under pressure, the nitrogen in the air dissolves into the tissues of the body. When the pressure is removed from the body, the dissolved nitrogen gas comes out of solution, causing painful and potentially life-threatening conditions known as Type I and Type II decompression sickness (also known as Caisson’s disease or "the bends"). Additionally, high partial pressures of nitrogen gas can impair brain function in a condition known as nitrogen narcosis.