N
Nitrogen
Element 7 · Reactive nonmetal
Nitrogen (N)
Nitrogen is a colourless, unreactive gas that makes up 78% of Earth’s atmosphere. It is an essential part of proteins and DNA.
- Reactive nonmetal
- Period 2
- Group 15
- p-block
- gas at room temperature
Key properties
- Atomic mass
- 14.007
- u
- Electron configuration
- [He] 2s2 2p3
- Melting point
- -210 °C
- 63.15 K
- Boiling point
- -195.8 °C
- 77.36 K
- Density
- 1.2506 g/L
- Electronegativity
- 3.04
- Pauling
- Atomic radius
- 155 pm
- van der Waals
- 1st ionisation energy
- 14.534 eV
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about nitrogen
- 01
The triple bond in N₂ is one of the strongest chemical bonds, which is why the gas is so inert.
- 02
The Haber–Bosch process turns atmospheric nitrogen into ammonia and helps feed roughly half the world’s population.
- 03
Liquid nitrogen boils at −196 °C and is used to freeze food and tissue in seconds.
Applications
What is nitrogen used for?
- Fertilisers (ammonia, nitrates)
- Food packaging atmosphere
- Cryogenic freezing
- Explosives
History
Discovery & name origin
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 7
- Atomic mass
- 14.007 u
- Group
- 15
- Period
- 2
- Block
- p-block
- Electron configuration
- [He] 2s2 2p3
- Full configuration
- 1s2 2s2 2p3
- Electrons per shell
- 2, 5
- Electronegativity (Pauling)
- 3.04
- Electron affinity
- —
- Atomic radius (van der Waals)
- 155 pm
- Stable isotopes
- 2
Oxidation states
Highlighted: common oxidation states (+5, +4, +3, +2, +1, -1, -2, -3).
Successive ionisation energies
Energy to remove each electron in turn (kJ/mol). Big jumps show where a new, inner shell begins.
- 1st1,402.3
- 2nd2,856
- 3rd4,578.1
- 4th7,475
- 5th9,444.9
- 6th53,266.6
- 7th64,360
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Gas
- Melting point
- 63.15 K · -210 °C · -346 °F
- Boiling point
- 77.36 K · -195.8 °C · -320.4 °F
- Density
- 1.2506 g/L
- Molar heat capacity
- —
- Appearance
- Colourless gas, liquid or solid
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Nitrogen questions
What is N on the periodic table?
N is the symbol for nitrogen, element 7 on the periodic table. It sits in group 15, period 2, in the reactive nonmetal category, and has an atomic mass of 14.007.
What is the atomic number of nitrogen?
Nitrogen has atomic number 7, so every nitrogen atom has 7 protons in its nucleus. Its symbol is N and its atomic mass is 14.007.
Who discovered nitrogen?
Nitrogen was discovered by Daniel Rutherford in 1772 (Scotland). The name comes from Greek nitron + genes, “niter-former”.
What is nitrogen used for?
Nitrogen is used for: fertilisers (ammonia, nitrates); food packaging atmosphere; cryogenic freezing; explosives.
Is nitrogen a metal?
No. Nitrogen is classed as a reactive nonmetal.
What is the electron configuration of nitrogen?
The electron configuration of nitrogen is [He] 2s2 2p3. Its 7 electrons are arranged in shells as 2, 5.