Reactive nonmetalElement 7 · p-block

Nitrogen (N)

Nitrogen (N) is a reactive nonmetal with atomic number 7 and a standard atomic weight of 14.007. At room temperature it is a gas that melts at -210 °C and boils at -196 °C.

7NNitrogen14.007

Atomic number

protons

Atomic weight

14.007

CIAAW 2024

Melting point

-210 °C

63.15 K

Boiling point

-196 °C

77.35 K

Density

1.2506 g/L

at 0 °C, 1 atm

Electronegativity

3.04

Pauling scale

State at 25 °C

Gas

Discovered

1772

Scotland

Nitrogen at a glance

Identity

Symbol	N
Atomic number (Z)	7
Atomic weight	14.007 ± 0.001 (CIAAW 2024)
Category	Reactive nonmetal
Group	15 — pnictogens (nitrogen group)
Period	2
Block	p-block
CAS number	7727-37-9

Atomic properties

Electron configuration	[He] 2s² 2p³ Full: 1s² 2s² 2p³
Electrons per shell	2, 5
Oxidation states	-3, +3, +5 Less common: -2, -1, 0, +1, +2, +4
Electronegativity (Pauling)	3.04
First ionisation energy	14.534 eV (1,402.3 kJ/mol) 2nd: 29.601 eV · 3rd: 47.445 eV
Atomic radius (empirical)	65 pm
Covalent radius	71 pm
Van der Waals radius	155 pm

Physical properties

State at 25 °C	Gas
Melting point	-210 °C · -346 °F · 63.15 K
Boiling point	-195.8 °C · -320.4 °F · 77.35 K
Density	1.2506 g/L (gas at 0 °C, 1 atm)
Specific heat capacity	1.04 J/(g·K)
Thermal conductivity	0.026 W/(m·K)
Crystal structure	Hexagonal

Isotopes & abundance

Natural occurrence	Primordial
Radioactive	No
Natural isotopes (abundance)	¹⁴N 99.6205%, ¹⁵N 0.3795%
Stable isotopes	4
Known isotopes	16
Abundance in Earth's crust	19 mg/kg
Abundance in seawater	0.5 mg/L

Atomic weights: CIAAW Abridged Standard Atomic Weights 2024. Other properties: standard reference compilations, checked October 2026; predicted values are marked.

Nitrogen electron configuration

Nitrogen has 7 electrons. Written in short form, its ground-state configuration is [He] 2s² 2p³ — the electrons of the noble gas helium, plus 2s² 2p³.Written out in full: 1s² 2s² 2p³.

As a member of group 15 it has 5 valence electrons in its outer shell (shell 2), which largely decide its chemistry.

2s↑↓

2p↑↑↑

Discovery and name

Discovered

1772 — Daniel Rutherford · Scotland.

Name

Greek nitron + genes — 'nitre-forming' (saltpetre).

Known for

Makes up about 78% of Earth's air. Fixed into ammonia by the Haber–Bosch process, it feeds roughly half the world's population via fertilisers; liquid nitrogen boils at −196 °C.

Isotopes of nitrogen

Naturally occurring nitrogen is a mix of 2 isotopes. Each has 7 protons; they differ in the number of neutrons:

Isotope	Protons	Neutrons	Natural abundance	Stability
¹⁴N	7	7	99.6205%	stable
¹⁵N	7	8	0.3795%	stable

16 isotopes of nitrogen are known in our data set (half-lives as published in nuclear data tables).

Nitrogen compared with group 15

The other elements in group 15 (pnictogens (nitrogen group)), from top to bottom of the table:

Element	Z	Atomic weight	Melting point	Boiling point	Density	Electronegativity
Nitrogen	7	14.007	-210 °C	-196 °C	1.2506 g/L	3.04
Phosphorus	15	30.974	44 °C	281 °C	1.823 g/cm³	2.19
Arsenic	33	74.922	—	614 °C	5.75 g/cm³	2.18
Antimony	51	121.76	631 °C	1,587 °C	6.68 g/cm³	2.05
Bismuth	83	208.98	271 °C	1,564 °C	9.79 g/cm³	2.02
Moscovium	115	[290]	—	—	13.5 g/cm³ (pred.)	—

Frequently asked questions

6 answers

What is the atomic mass of nitrogen?

The standard atomic weight of nitrogen is 14.007 ± 0.001 (CIAAW 2024), so one mole weighs about 14.007 grams.

How many protons, neutrons and electrons does nitrogen have?

A neutral nitrogen atom has 7 protons and 7 electrons. Its most common isotope, nitrogen-14, has 7 neutrons.

What is the electron configuration of nitrogen?

[He] 2s² 2p³ (in full: 1s² 2s² 2p³).

What are the melting and boiling points of nitrogen?

Nitrogen melts at -210 °C (-346 °F) and boils at -195.8 °C (-320.4 °F).

Is nitrogen a metal?

Nitrogen is a nonmetal. It is in group 15, period 2, and is a gas at room temperature.

Who discovered nitrogen?

1772 — Daniel Rutherford (Scotland).