Template:Infobox chlorine

Chlorine,  ₁₇Cl

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General properties
Pronunciation	Template:Infobox element/pronunciation
Appearance	pale yellow-green gas
Standard atomic weight (Ar, standard)	Template:Infobox element/standard atomic weight
Mass number	Template:Infobox element/symbol-to-most-stable-isotope (most stable isotope)
Chlorine in the periodic table
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Atomic number (Z)	17
Group	Template:Infobox element/group
Period	period 3
Block	p-block
Element category	Template:Infobox element/category format
Electron configuration	[Ne] 3s2 3p5
Electrons per shell	2, 8, 7
Physical properties
Phase at STP	gas
Melting point	171.6 K ​(−101.5 °C, ​−150.7 °F)
Boiling point	239.11 K ​(−34.04 °C, ​−29.27 °F)
Density (at STP)	3.2 g/L
when liquid (at b.p.)	1.5625 g/cm3
Critical point	416.9 K, 7.991 MPa
Heat of fusion	(Cl2) 6.406 kJ/mol
[[Enthalpy of vaporization|Heat of Template:Engvar]]	(Cl2) 20.41 kJ/mol
Molar heat capacity	(Cl2) 33.949 J/(mol·K)
[[Vapor pressure|Template:Engvar pressure]] Template:Infobox element/vapor pressure table
Atomic properties
Oxidation states	Template:Infobox element/symbol-to-oxidation-state
Electronegativity	Pauling scale: 3.16
[[Ionization energy|Template:Engvar energies]]	1st: 1251.2 kJ/mol 2nd: 2298 kJ/mol 3rd: 3822 kJ/mol (more)
Covalent radius	102±4 pm
Van der Waals radius	175 pm
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Other properties
Crystal structure	​Template:Infobox element/crystal structure Template:Infobox element/crystal structure
Speed of sound	206 m/s (gas, at 0 °C)
Thermal conductivity	8.9Template:E W/(m·K)
Electrical resistivity	>10 Ω·m (at 20 °C)
Magnetic ordering	diamagnetic
Magnetic susceptibility	−40.5·10−6 cm3/mol
CAS Number	7782-50-5
History
Discovery and first isolation	Carl Wilhelm Scheele (1774)
Recognized as an element by	Humphry Davy (1808)
Main isotopes of chlorine
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