Nitrogen (N)

Nitrogen properties

Atomic number

7

Atomic mass

14.007 u

Category

Reactive nonmetal

Group

15

Period

2

Block

p-block

State at room temp.

Gas

Electronegativity

3.04

Melting point

63.15 K (-210 °C)

Boiling point

77.36 K (-195.8 °C)

Density

1.251 g/L

Valence electrons

5

Common charges

−3

Oxidation states

+5, +4, +3, +2, +1, −1, −2, −3

Atomic radius

155 pm

Ionization energy

14.534 eV

Electron affinity

—

Radioactive

No, has stable isotopes

Discovered

1772

Nitrogen electron configuration

The electron configuration of Nitrogen (N) is [He] 2s2 2p3. Its 7 electrons are arranged in shells as 2, 5.

Protons, neutrons and electrons in Nitrogen

A neutral Nitrogen atom has 7 protons and 7 electrons. Most Nitrogen atoms have about 7 neutrons: the atomic mass rounded to 14, minus the atomic number 7.

Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass

How many valence electrons does Nitrogen have?

5

Nitrogen has 5 valence electrons in its outermost shell, shell 2. These are the electrons involved in chemical bonding.

See every element: Periodic table with valence electrons

Nitrogen orbital diagram

Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations

Molar mass of Nitrogen

14.007 g/mol

One mole of Nitrogen atoms (6.022 × 10²³ atoms) has a mass of 14.007 grams. Use this value to convert between grams and moles.

Compounds containing Nitrogen

Nitrogen facts

• Nitrogen makes up about 78% of the air we breathe, by volume.
• Living things need nitrogen to build proteins and DNA, but most cannot use nitrogen gas directly and rely on microbes that 'fix' it into usable compounds.
• Nitrogen (N) has atomic number 7 and is a gas at room temperature. It was discovered in 1772.

Position in the periodic table

Nitrogen is element 7, in period 2 and group 15 of the periodic table, in the p-block.

All nonmetals

Uses of Nitrogen

Nitrogen is turned into ammonia on a huge scale to make fertilizers, and into nitric acid for explosives and other chemicals. Because it is unreactive, nitrogen gas is pumped into food packaging, such as bags of chips, to keep the contents fresh, and it protects electronics during manufacturing. Liquid nitrogen, at −196 °C, freezes food quickly, preserves biological samples and is used to remove warts.

Who discovered Nitrogen?

Scottish physician Daniel Rutherford discovered nitrogen in 1772 in Edinburgh, isolating the part of air that would not support burning or breathing, which he called 'noxious air'. Carl Wilhelm Scheele, Henry Cavendish and Joseph Priestley studied the gas independently at around the same time.

Where does the name come from?

Nitrogen means 'niter-former', from niter (saltpeter) and the Greek genes, 'forming', because the gas is part of niter. Jean-Antoine Chaptal coined the name in 1790; niter itself goes back to the Greek nitron.

Discovery timeline