The density of N2, or a nitrogen molecule, at 20 degrees Celsius is 1.165 kilograms per cubic meter. Its density at 0 degrees Celsius is 1.2506 kilograms per cubic meter. The critical density of nitrogen is 313.3 kilograms per cubic meter.
In the liquid state, its density is 806.11 kilograms per cubic meter at its boiling point. Nitrogen is a gas at room temperature, and it constitutes 78 percent of the Earth’s atmosphere. Its atomic number is 7, and the symbol is N. Under standard conditions of temperature and pressure, nitrogen is a colorless and tasteless gas. All living organisms contain nitrogen in some form. Ammonia and nitric acid are two useful compounds of nitrogen.