--- title: "Nitrogen (N) — element 7" description: "Nitrogen is element 7, symbol N, atomic weight 14.007. Configuration, properties, uses and neighbours." url: https://atoneplace.net/element/nitrogen/ site: "At One Place" --- # Nitrogen (N) **Nitrogen — element 7: N** 14.007 u · Nonmetal · period 2, group 15 The N≡N triple bond is one of the strongest in chemistry, which is why nitrogen makes up 78% of the air and almost nothing happens to it. Breaking that bond industrially — the Haber-Bosch process, run at roughly 450 °C and 200 atmospheres — consumes on the order of 1-2% of world energy production, and the nitrogen in roughly half the protein in the human body has been through it. The same stubborn bond is why nitrogen compounds make good explosives: the products want to become N₂, and releasing that much bond energy at once is what an explosion is. ## Properties - **Atomic number:** 7 - **Symbol:** N - **Standard atomic weight:** 14.007 u - **Category:** Nonmetal - **Group:** 15 - **Period:** 2 - **Block:** p-block - **Electron configuration:** [He] 2s² 2p³ - **Electrons per shell:** 2, 5 - **Melting point:** 63.15 K — -210.0 °C — -346.0 °F - **Boiling point:** 77.36 K — -195.8 °C — -320.4 °F - **Density:** 0.0012506 g/cm³ - **Electronegativity:** 3.04 (Pauling) - **Oxidation states:** +5, +4, +3, +2, +1, -1, -2, -3 - **Discovered:** 1772 by Daniel Rutherford ## Electron configuration - **Full:** 1s² 2s² 2p³ - **Noble gas shorthand:** [He] 2s² 2p³ - **Shells:** K: 2 · L: 5 ## What it is used for - Ammonia for fertiliser, which feeds roughly half the world - Liquid nitrogen for freezing biological samples and food - An inert blanket in food packaging, wine tanks and fuel systems - Nitric acid for explosives, dyes and nylon - Purging and pressure-testing pipework ## Hazards - Asphyxiation risk in confined spaces — it displaces oxygen without warning - Liquid nitrogen at 77 K causes severe cold burns and can shatter sealed containers > IUPAC publishes an interval, [14.00643, 14.00728]; 14.007 is the conventional value. Density is the gas at 0 °C and 101.325 kPa; liquid nitrogen is 0.807 g/cm³. ## Neighbours in the table | Z | Element | Symbol | Mass | | --- | --- | --- | --- | | 5 | Boron | B | 10.81 | | 6 | Carbon | C | 12.011 | | 7 | Nitrogen ← | N | 14.007 | | 8 | Oxygen | O | 15.999 | | 9 | Fluorine | F | 18.998 | ## Group 15 Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Nitrogen sits in group 15 with phosphorus, arsenic, antimony, bismuth, moscovium. ## Common questions ### What is the atomic number of nitrogen? 7. That is the number of protons in its nucleus, which is what defines the element. ### What is the symbol for nitrogen? N. ### What is the electron configuration of nitrogen? 1s² 2s² 2p³, or [He] 2s² 2p³ in noble-gas shorthand. ### What is the melting point of nitrogen? 63.15 K — -210.0 °C — -346.0 °F ## Related pages - [Boron (B)](https://atoneplace.net/element/boron/) - [Carbon (C)](https://atoneplace.net/element/carbon/) - [Oxygen (O)](https://atoneplace.net/element/oxygen/) - [Fluorine (F)](https://atoneplace.net/element/fluorine/) - [Phosphorus (P)](https://atoneplace.net/element/phosphorus/) - [Arsenic (As)](https://atoneplace.net/element/arsenic/) - [Antimony (Sb)](https://atoneplace.net/element/antimony/) - [Bismuth (Bi)](https://atoneplace.net/element/bismuth/) - [Moscovium (Mc)](https://atoneplace.net/element/moscovium/) ## Sources - Official vendor product documentation — At One Place (/about/)