Nitrogen
diatomic nonmetal · period 2 · group 15 (pnictogens) · p-block
Nitrogen is the chemical element with the symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772.
What the numbers say
At standard temperature and pressure Nitrogen is a gas, sitting in period 2, group 15 of the p-block.
Its melting point of 63 K (-210 °C) is the 105th highest of the 110 elements with a measured value — among the lowest-melting elements.
At 0.001 g/cm³ it is the 93rd densest of 96 elements with a quoted density.
Pauling electronegativity is 3.04. Paired with oxygen (3.44) that is a difference of 0.40, which puts the bond essentially covalent, so the oxide behaves as a molecular or network solid.
In the solid state it takes a simple hexagonal structure — hexagonal packing offers few easy slip systems, so properties are anisotropic and formability is limited.
It is reported in 8 oxidation states (-3, -2, -1, 1, 2, 3, 4, 5), which sets how many distinct compounds and phases it can form.
First identified in 1772.
Crystal structure
Solid Nitrogen adopts a Simple Hexagonal arrangement, in the Hexagonal system — axes a = b ≠ c, angles α = β = 90°, γ = 120°. Symmetry controls the anisotropy of stiffness and thermal expansion, and the available slip systems set how far the metal deforms before it fractures.
Check it against computed structures
The structure search queries the Materials Project, OQMD and the Open Materials Database for computed crystal structures containing N — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 5
Properties
| Atomic number | 7 |
|---|---|
| Atomic mass | 14.007 u |
| Series | diatomic nonmetal |
| Group | 15 |
| Period | 2 |
| Block | p-block |
| Phase at STP | Gas |
| Density | 0.001 g/cm³ |
| Melting point | 63.15 K (-210 °C) |
| Boiling point | 77.36 K (-196 °C) |
| Electronegativity (Pauling) | 3.04 |
| Electron configuration | [He] 2s² 2p³ |
| Crystal structure | Simple Hexagonal |
| Oxidation states | -3,-2,-1,1,2,3,4,5 |
| Discovered | 1772 |
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See N in context with all 118 elements.
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