Nitrogen
Nitrogen (N) is a reactive nonmetal with atomic number 7 and an atomic mass of 14.007. Its electron configuration is [He] 2s2 2p3, which gives it 5 valence electrons.
Nitrogen key data
| Symbol | N |
|---|---|
| Atomic number | 7 |
| Atomic mass (standard atomic weight) | 14.007 |
| Molar mass | 14.007 g/mol |
| Protons | 7 |
| Neutrons (most abundant isotope, nitrogen-14) | 7 |
| Electrons (neutral atom) | 7 |
| Valence electrons | 5 |
| Category | Reactive nonmetal |
| Period | 2 |
| Group | 15 |
| Block | p-block |
| Noble gas notation | [He] 2s2 2p3 |
| Full electron configuration | 1s2 2s2 2p3 |
| Electrons per shell | 2, 5 |
Atomic mass: IUPAC CIAAW abridged standard atomic weights, 2024. Most abundant isotope: NIST Atomic Weights and Isotopic Compositions.
The values are facts and free to use; this page’s selection and presentation are © 2026 ScienceQuest.
Measured properties of nitrogen
From PubChem, the US National Institutes of Health. Public domain. PubChem’s periodic table gives no value for the rows not shown.
| Melting point | 63.15 K (−210 °C), 98th of 103 by melting point |
|---|---|
| Boiling point | 77.36 K (−195.79 °C), 90th of 93 by boiling point |
| Density | 0.001251 g/cm³, 93rd of 96 by density |
| State at room temperature | Gas |
| Electronegativity | 3.04 (Pauling), 4th of 95 by electronegativity |
| Van der Waals radius | 155 pm, 91st of 99 by atomic radius |
| First ionisation energy | 14.534 eV (1402.3 kJ/mol), 5th of 102 by first ionisation energy |
| Common oxidation states | +5, +4, +3, +2, +1, −1, −2, −3 |
| Discovered | 1772 |
Each rank counts down from the highest value, among the elements PubChem’s table gives one for, and links to that property ranked across the whole table. All of them are collected under periodic trends.
Nitrogen electron configuration
The full electron configuration of nitrogen is 1s2 2s2 2p3. With the noble-gas core collapsed it is [He] 2s2 2p3, and the outermost subshell is 2p3.
Why group and block follow from this is set out in how the periodic table maps electron configuration, and the electron configuration of every element is listed on one page.
Mass of one nitrogen atom
A molar mass is grams per mole, so dividing by the Avogadro constant gives the mass of a single atom, or for an element with more than one natural isotope the average mass of its atoms, and the reciprocal gives how many atoms sit in a gram.
Mass of one atom
- one atom = 14.007 / (6.02214076 × 10²³)
- = 2.3259 × 10⁻²³ g
Atoms in one gram
- atoms per gram = 6.02214076 × 10²³ / 14.007
- = 4.2994 × 10²² atoms
Nitrogen on the periodic table
Nitrogen is in period 2, group 15, in the p-block.
The other elements of group 15 are phosphorus, arsenic, antimony, bismuth and moscovium.