Nitrogen links the atmosphere to living molecules. Plants incorporate nitrogen compounds into the building blocks of proteins and genetic material. Industrial ammonia production combines nitrogen with hydrogen, supplying a route to fertilizers, while liquid nitrogen provides very low temperatures for cooling and preservation.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
How can nitrogen slow oxygen-related food changes without sterilising the package?
Nitrogen gas
FOLLOW THIS RELATIONSHIP
Identify the unwanted exposure
Some food changes depend on contact with oxygen in the package atmosphere; reducing that contact addresses a particular pathway rather than every deterioration process.
Explore the model (optional)
NFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Atomic identity, reference properties and structure models
INTERACTIVE 3D2 visible sites
N₂ · two atoms, one moleculeDrag to rotate · scroll or pinch to zoom
An elemental molecule has more than one atom but only one element. A single connector identifies the molecular pair; bond order and electron density are not encoded.
What this representation means
Original idealized molecular geometry. Display sizes are illustrative; this is not a measured coordinate dataset.
Eighteenth-century investigators learned that air was a mixture by removing components and examining what remained. Cavendish and Priestley obtained gas that would not support burning, but did not identify it as an element. In his 1772 thesis, Rutherford distinguished the residual gas. The discovery illustrates how the absence of an expected reaction can become evidence, provided the preparation and comparison are understood.
1760s
Residual gas studied
Cavendish and Priestley investigated air after removing its oxygen component.
1772
Distinct gas described
Rutherford reported the properties of the residual gas in his doctoral work.
Nitrogen gas forms much of Earth's atmosphere, while nitrogen compounds occur in , soils, fertilizers, and other materials. Biological nitrogen fixation brings atmospheric nitrogen into forms organisms can use. The nitrogen in a leaf or a fertilizer is chemically situated differently from the nitrogen molecules around it.
Nitrogen gas is comparatively unreactive under many everyday conditions, but nitrogen compounds span very different behaviors. Ammonia and nitrates illustrate that difference. Cooling nitrogen gives a liquid useful for low-temperature work; this physical change preserves elemental composition while changing the state and handling requirements.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
gas
293.15 K, 101.325 kPa
Melting point in K
63.15 K
at standard pressure unless noted
Boiling point in K
77.36 K
101.325 kPa
Density in g/cm³
0.00125 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
3.04 Pauling
Pauling scale
First ionization energy in kJ/mol
1402 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
71 pm
single-bond covalent radius
Common oxidation states
-3, +3, +5
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
19 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year in CE
1772 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 2
N 3.04 Pauling · Nitrogen
Electronegativity across period 2. Exact values.
Li
0.98
Be
1.57
B
2.04
C
2.55
N
3.04
O
3.44
F
3.98
Electronegativity down group 15
N 3.04 Pauling · Nitrogen
Electronegativity down group 15. Exact values.
N
3.04
P
2.19
As
2.18
Sb
2.05
Bi
2.02
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
