((Infobox element
|engvar =(({engvar|))}
|name   =chlorine
|symbol =Cl
|Z      =17
|number =17
|abundance=
|abundance in earth's crust=
|abundance in oceans=
|abundance in solar system=
|left=[[sulfur]]
|right=[[argon]]
|above=[[fluorine|F]]
|below=[[bromine|Br]]
|appearance=pale yellow-green gas
|image name=File:Chlorine in bottle.jpg
|electrons per shell=2, 8, 7
|phase=
|phase comment=
|density gplstp=3.2
|density gpcm3nrt=
|density gpcm3nrt 2=
|density gpcm3mp=
|density gpcm3bp=1.5625
|density gpcm3bp ref=<ref>[http://encyclopedia.airliquide.com/Encyclopedia.asp?LanguageID=11&CountryID=19&Formula=&GasID=13&UNNumber=&EquivGasID=3&PressionBox=&VolLiquideBox=&MasseLiquideBox=&VolGasBox=&MasseGasBox=&RD20=29&RD9=8&RD6=64&RD4=2&RD3=22&RD8=27&RD2=20&RD18=41&RD7=18&RD13=71&RD16=35&RD12=31&RD19=34&RD24=62&RD25=77&RD26=78&RD28=81&RD29=82 Chlorine], Gas Encyclopaedia, Air Liquide</ref>
|melting point prefix=(Cl<sub>2</sub>)
|melting point K=171.6
|melting point C=−101.5
|melting point F=−150.7
|boiling point prefix=(Cl<sub>2</sub>)
|boiling point K=239.11
|boiling point C=−34.04
|boiling point F=−29.27
|triple point K=172.22
|triple point kPa=1.392
|triple point ref=<ref>((cite journal | last=Ambrose | first=D | last2=Hall | first2=D.J | last3=Lee | first3=D.A | last4=Lewis | first4=G.B | last5=Mash | first5=C.J | title=The vapour pressure of chlorine | journal=The Journal of Chemical Thermodynamics | volume=11 | date=1979 | doi=10.1016/0021-9614(79)90139-3 | pages=1089–1094))</ref>
|critical point K=416.9
|critical point MPa=7.991
|heat fusion=(Cl<sub>2</sub>) 6.406
|heat fusion 2=
|heat vaporization=(Cl<sub>2</sub>) 20.41
|heat capacity=(Cl<sub>2</sub>)<br/>33.949
|vapor pressure 1=128
|vapor pressure 10=139
|vapor pressure 100=153
|vapor pressure 1 k=170
|vapor pressure 10 k=197
|vapor pressure 100 k=239
|vapor pressure comment=
|crystal structure=orthorhombic
|crystal structure Pearson symbol=oS8
|lattice constants=''a''&nbsp;=&nbsp;630.80&nbsp;pm<br />''b''&nbsp;=&nbsp;455.83&nbsp;pm<br />''c''&nbsp;=&nbsp;815.49&nbsp;pm (at&nbsp;triple&nbsp;point)<ref name="Arblaster 2018">((cite book |last=Arblaster |first= John W. |title=Selected Values of the Crystallographic Properties of Elements |publisher=ASM International |publication-place=Materials Park, Ohio |date=2018 |isbn=978-1-62708-155-9))</ref>
|electronegativity=3.16
|number of ionization energies=4
|ionization energy 1=1251.2
|ionization energy 2=2298
|ionization energy 3=3822
|atomic radius=
|atomic radius calculated=
|covalent radius=102±4
|Van der Waals radius=175
|magnetic ordering=[[diamagnetic]]
|magnetic ordering ref=<ref>[http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elementmagn.pdf Magnetic susceptibility of the elements and inorganic compounds], in ((RubberBible86th))</ref>
|electrical resistivity=
|electrical resistivity at 0=
|electrical resistivity at 20=&gt;10
|thermal conductivity=8.9((e|-3))
|thermal conductivity 2=
|thermal diffusivity=
|thermal expansion=
|thermal expansion at 25=
|speed of sound=206
|speed of sound comment=(gas, at&nbsp;0&nbsp;°C)
|speed of sound rod at 20=
|speed of sound rod at r.t.=
|magnetic susceptibility= ((val|-40.5|e=−6))
|magnetic susceptibility ref= <ref>((Cite book|title=CRC, Handbook of Chemistry and Physics|last=Weast|first=Robert|publisher=Chemical Rubber Company Publishing|year=1984|isbn=0-8493-0464-4|location=Boca Raton, Florida|pages=E110))</ref>
|Young's modulus=
|Shear modulus=
|Bulk modulus=
|Poisson ratio=
|Mohs hardness=
|Vickers hardness=
|Brinell hardness=
|CAS number=Cl<sub>2</sub>: 7782-50-5
|discovery and first isolation by=[[Carl Wilhelm Scheele]]
|discovery date=1774
|history comment label=Recognized as an [[chemical element|element]] by
|history comment=[[Humphry Davy]] (1808)
|QID=Q688
))<!--

--><noinclude>
((Infobox element/element navigation|symbol=Cl))
((Template reference list))
((documentation|1=Template:Infobox element/doc))
</noinclude>