Symbol: N
Atomic number: 7
Category: nonmetals
Group: 15
Period: 2
Block: p
Atomic weight: 14.0067 g/mol
Electrons per shell: 2, 5
CAS number: 7727-37-9
Phase: gas
Density: 1.251 g/l (0 C, 101.325 kPa)
Melting point: 63.153 K (-210.00 C, -346.00 F)
Boiling point: 77.36 K (-195.79 C, -320.3342 F)
Crystal structure: hexagonal
Oxidation states: 5, 4, 3, 2, 1, -1, -3
Electronegativity: 3.04 (Pauling scale)
Name's origin: nitrogenium
Name's meaning: the Latin word for 'saltpetre' (nitrum) and 'forming' (genes) - forms potassium nitrate
- is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions
- constitutes 78 % by volume of Earth's atmosphere
- many industrially important compounds, such as ammonia, nitric acid, organic nitrates (propellants and explosives), and cyanides, contain nitrogen
- is created by fusion processes in stars, and is estimated to be the 7th most abundant chemical element by mass in the universe
- is a constituent element of amino acids and thus of proteins, and of nucleic acids (DNA and RNA)
- is used widely as an industrial gas: e.g. to preserve the freshness of packaged or bulk foods, in ordinary incandescent light bulbs on top of liquid explosives and in the manufacturing of stainless steel
- rapid release of nitrogen gas into an enclosed space can displace oxygen, and therefore represents an asphyxiation hazard