Nitrogen,  ₇N

General properties
Appearance	colorless gas, liquid or solid
Standard atomic weight (Ar, standard)	[14.00643, 14.00728]
Nitrogen in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson – ↑ N ↓ P carbon ← nitrogen → oxygen
Atomic number (Z)	7
Group	group 15 (pnictogens)
Period	period 2
Block	p-block
Element category	reactive nonmetal
Electron configuration	[He] 2s2 2p3
Electrons per shell	2, 5
Physical properties
Phase at STP	N: Gas
Melting point	63.15 K ​(−210.00 °C, ​−346.00 °F)
Boiling point	77.355 K ​(−195.795 °C, ​−320.431 °F)
Density (at STP)	1.2504 g/L at 0 °C, 1013 mbar
when liquid (at b.p.)	0.808 g/cm3
Triple point	63.151 K, ​12.52 kPa
Critical point	126.192 K, 3.3958 MPa
Heat of fusion	(N2) 0.72 kJ/mol
Heat of vaporization	(N2) 5.56 kJ/mol
Molar heat capacity	(N2) 29.124 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 37 41 46 53 62 77
Atomic properties
Oxidation states	−3, −2, −1, +1, +2, +3, +4, +5 (a strongly acidic oxide)
Electronegativity	Pauling scale: 3.04
Ionization energies	1st: 1402.3 kJ/mol 2nd: 2856 kJ/mol 3rd: 4578.1 kJ/mol (more)
Covalent radius	71±1 pm
Van der Waals radius	155 pm
Spectral lines of nitrogen
Other properties
Natural occurrence	N: Primordial
Crystal structure	​hexagonal
Speed of sound	353 m/s (gas, at 27 °C)
Thermal conductivity	25.83×10−3 W/(m·K)
Magnetic ordering	diamagnetic
CAS Number	17778-88-0 7727-37-9 (N2)
History
Discovery	Daniel Rutherford (1772)
Named by	Jean-Antoine Chaptal (1790)
Main isotopes of nitrogen
Iso­tope Abun­dance Half-life (1/2) Decay mode Pro­duct 13N syn 9.965 min ε 13C 14N 99.6% stable 15N 0.4% stable
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Nitrogen is a nonmetal chemical element. The atmosphere contains more than 78 percent of nitrogen. It has the chemical symbol N and atomic number 7. Its stable inside typically contains 14 nucleons (7 protons and 7 neutrons). It has 5 electrons in its outer shell.