Periodic Table

Nitrogen

Nonmetal

Quick Facts about Nitrogen

C
  • gas- state of matter at room temperature
  • Stable- has at least one stable isotope
  • +5, +4, +3, +2, +1, -1, -2, -3- common oxidation states in compounds
  • HEX- crystal structure, atomic arrangement in solid form
O

Nitrogen (N) is element 7 on the periodic table. Atomic mass of N: 14.0070 u. N is in period 2, group 15. Melting point of N: 63.15 K.Density of N: 0.00 g/cm³.

Why Nitrogen Matters

The invisible majority—78% of every breath you take is nitrogen

In Your Home

  • The air around you (78% nitrogen)
  • Food preservative in chip bags (keeps them fresh)
  • Fertilizers in your garden
  • Liquid nitrogen for wart removal at the doctor

Industry Uses

AgricultureAmmonia and nitrate fertilizers feed half the world's population
FoodModified atmosphere packaging extends food shelf life
CryogenicsLiquid nitrogen (-196°C) for freezing and cooling
ElectronicsInert atmosphere for semiconductor manufacturing

In Your Body

✓ Essential for life

Essential component of amino acids, proteins, and DNA. Makes up 3% of human body mass. Plants need 'fixed' nitrogen (ammonia/nitrates) from soil bacteria or fertilizers.

Safety: N2 gas is inert and non-toxic but can cause asphyxiation by displacing oxygen. Nitrogen narcosis affects divers at depth.

Discovery of Nitrogen

Discovered by Daniel Rutherford in Scotland, 1772

Name origin: Greek: nitron and genes, (soda forming).

History & Events

1772
Discovery
Daniel Rutherford identified 'noxious air' (nitrogen) that couldn't support combustion or life
1909
Haber Process
Fritz Haber synthesized ammonia from nitrogen, enabling mass fertilizer production—and explosives
1995
Airbag Chemistry
Sodium azide decomposition to produce nitrogen gas became standard for car airbags

About Nitrogen

Colorless, gaseous element which belongs to group 15 of the periodic table. Constitutes ~78% of the atmosphere and is an essential part of the ecosystem. Nitrogen for industrial purposes is acquired by the fractional distillation of liquid air. Chemically inactive, reactive generally only at high temperatures or in electrical discharges. It was discovered in 1772 by D. Rutherford.

Atomic Properties of N

Atomic Number of N
7
Atomic Mass of N
14.0070 u
Electron Configuration
[He] 2s2 2p3
Electronegativity
3.04
Block
p-block
Group
15
Period
2

Physical Properties of N

Phase (STP)
gas
Melting Point of N
63.15 K
Boiling Point of N
77.36 K
Density of N
0.0013 g/cm3

Thermal Properties

Specific Heat
1.04 J/g·K
Molar Heat Capacity
29.12 J/mol·K
Thermal Conductivity
0.03 W/m·K

Atomic Radii

Calculated
65 pm
Covalent
71 pm
Van der Waals
155 pm

Common Misconceptions

Wrong:We breathe nitrogen for energy.
Correct:We inhale N2 and exhale it unchanged. Our bodies can't use atmospheric nitrogen directly—we get it from food.
Wrong:Nitrogen is dangerous in food.
Correct:N2 gas in food packaging is completely safe. It's inert and just prevents oxidation.
Wrong:Adding nitrogen to tires is a scam.
Correct:Nitrogen-filled tires do leak slower and fluctuate less with temperature, but the benefit is modest for regular driving.

Allotropes of Nitrogen

Nitrogen exists in 2 different structural forms (allotropes), each with unique properties.

Dinitrogen (N2)

Stable diatomic gas making up 78% of atmosphere

Structure:Triple-bonded N≡N molecule
Properties:Colorless, odorless, very stable, inert at room temperature

Trinitrogen (N3)

Unstable azide radical

Structure:Linear triatomic
Properties:Highly reactive, short-lived

Isotopes of Nitrogen

Nitrogen has 2 naturally occurring isotopes, plus 1 notable radioactive isotope.

IsotopeAtomic Mass (u)AbundanceHalf-LifeDecay Mode
137N (N-13)Nitrogen-13 isotope13.005738610%9.97 minutesβ⁺
147N (N-14)Nitrogen-14 isotope14.00307499.64%
157N (N-15)Nitrogen-15 isotope15.00010890.3640%

Data source: NIH PubChem (aggregated from IUPAC, NIST)

Isotope Applications

Isotopes of Nitrogen have important real-world applications in science and industry.

Industrial Applications

15N is widely used as a stable isotope tracer in agricultural research to study nitrogen fixation, fertilizer uptake, and nitrogen cycling in ecosystems. It is also essential in NMR spectroscopy for studying protein structure and dynamics.

Medical Applications

13N is used in positron emission tomography (PET) imaging to study blood flow and metabolism, particularly in cardiac imaging. Its short half-life (10 minutes) requires on-site production via cyclotron.

Abundance

Earth's Crust
19.0 mg/kg
Seawater
500.00 μg/kg

Uses

Primarily to produce ammonia and other fertilizers. Also used in making nitric acid, which is used in explosives. Also used in welding and enhanced oil recovery.

Sources

Obtained from liquid air by fractional distillation.

Geochemistry

Goldschmidt
atmophile
Geochemical Class
volatile

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