Chlorine

Chlorine (Cl)

Chlorine is the 17th element in the periodic table and has a symbol of Cl and atomic number of 17. It has an atomic weight of 35.450 and a mass number of 35. Chlorine has seventeen protons and eighteen neutrons in its nucleus, and seventeen electrons in three shells. It is located in group seventeen, period three and block p of the periodic table. Halogen element. Poisonous greenish-yellow gas. Occurs widely in nature as sodium chloride in seawater. Reacts directly with many elements and compounds, strong oxidizing agent. Discovered by Karl Scheele in 1774. Humphrey David confirmed it as an element in 1810.
Atomic Number17
Atomic Weight35.45
Mass Number35
Group17
Period3
Blockp
Protons17 p+
Neutrons18 n0
Electrons17 e-
Animated Bohr Model of Cl (Chlorine)

Physical Properties

Atomic Radius
100 pm
Molar Volume
Covalent Radius
99 pm
Metallic Radius
Ionic Radius
181 pm
Crystal Radius
167 pm
Van der Waals Radius
175 pm
Density
0.002898 g/cm³
Atomic Radii of the Elements: Chlorine0102030405060708090100110120130140150160170180pmAtomic RadiusCovalent RadiusMetallic RadiusVan der Waals Radius

Chemical Properties

Energy
Proton Affinity
513.6 kJ/mol
Electron Affinity
3.612725 eV/particle
Ionization Energy
12.96763 eV/particle
Ionization Energies of Cl (Chlorine)
Heat of Vaporization
20.41 kJ/mol
Heat of Fusion
6.41 kJ/mol
Heat of Formation
121.302 kJ/mol
Electrons
Electron Shells2, 8, 7
Bohr Model: Cl (Chlorine)
Valence Electrons7
Lewis Structure: Cl (Chlorine)
Electron Configuration[Ne] 3s2 3p5
1s2 2s2 2p6 3s2 3p5
Enhanced Bohr Model of Cl (Chlorine)
Orbital Diagram of Cl (Chlorine)
Oxidation States-1, 1, 2, 3, 4, 5, 6, 7
Electronegativity
3.16
Electrophilicity Index
3.673315922583194 eV/particle
States of Matter
PhaseGas
Gas PhaseDiatomic
Boiling Point
239.11 K
Melting Point
171.65 K
Critical Pressure
7.991 MPa
Critical Temperature
417.05 K
Triple Point
Visual

Chlorine is a Yellow. Cl has a CPK of #00ff00, Jmol of #1ff01f, and MOLCAS GV of #38b538. The Appearance of Element 17 is pale yellow-green gas. The Refractive Index of Chlorine (Cl) is 1.000773.

Color
Yellow
Appearancepale yellow-green gas
Refractive Index
1.000773
Thermodynamic Properties
Thermal Conductivity
0.009 W/(m K)
Thermal Expansion
Molar Heat Capacity
33.949 J/(mol K)
Specific Heat Capacity
0.479 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)7/5
Electrical Properties
TypeInsulator
Electrical Conductivity
0.00000001 MS/m
Electrical Resistivity
100 m Ω
Superconducting Point
Magnetism
Typediamagnetic
Magnetic Susceptibility (Mass)
-0.0000000072 m³/Kg
Magnetic Susceptibility (Molar)
-0.000000000511 m³/mol
Magnetic Susceptibility (Volume)
-0.0000000231
Magnetic Ordering
Curie Point
Neel Point
Structure

The Crystal Structure of Chlorine is ORC. The lattice constant of Cl is 6.24 Å. The lattice angles of Element 17 are π/2, π/2, π/2.

Crystal StructureBase Centered Orthorhombic (ORC)
Lattice Constant
6.24 Å
Lattice Anglesπ/2, π/2, π/2
Mechanical Properties

The Bulk Modulus of Chlorine is 1.1 GPa. The Speed of Sound of Cl is 206 m/s.

Hardness
Bulk Modulus
1.1 GPa
Shear Modulus
Young's Modulus
Poisson Ratio
Speed of Sound
206 m/s
Classification

The CAS Group of Chlorine is VIIB. The IUPAC Group of Cl is VIIA. The Glawe Number of Element 17 is 101. The Mendeleev Number of Chlorine (Cl) is 107. The Pettifor Number of Chlorine is 99. The Geochemical Class of Cl is semi-volatile. The Goldschmidt Class of Element 17 is litophile.

CategoryHalogens, Halogens
CAS GroupVIIB
IUPAC GroupVIIA
Glawe Number101
Mendeleev Number107
Pettifor Number99
Geochemical Classsemi-volatile
Goldschmidt Classlitophile

Other

The Gas Basicity of Chlorine is 490.1 kJ/mol. The Dipole Polarizability of Cl is 14.6 plus or minus 0.1 a₀. Element 17 has a C6 Dispersion Coefficient (CD) of 94.6 a₀, and C6 Dispersion Coefficient (GB) of 97.1 a₀. The Allotropes of Chlorine (Cl) is Dichlorine. The Neutron Cross Section of Chlorine is 35.3. The Neutron Mass Absorption of Cl is 0.033. The Quantum Numbers of Element 17 is 2P3/2. The Space Group of Chlorine (Cl) is 64 (Cmca).

Gas Basicity
490.1 kJ/mol
Dipole Polarizability
14.6 ± 0.1 a₀
C6 Dispersion Coefficient
94.6 a₀
AllotropesDichlorine
Neutron Cross Section
35.3
Neutron Mass Absorption
0.033
Quantum Numbers2P3/2
Space Group64 (Cmca)

Isotopes of Chlorine

Stable Isotopes2
Unstable Isotopes23
Natural Isotopes2
Isotopic Composition3575.80%3575.80%3724.20%3724.20%

28Cl

Mass Number28
Neutron Number11
Relative Atomic Mass
28.030349 ± 0.000537 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
Spin1
Quadrupole Moment
Discovery Year2018
Parity+

Decay ModeIntensity
p (proton emission)100%

29Cl

Mass Number29
Neutron Number12
Relative Atomic Mass
29.015053 ± 0.000203 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
5.4 ± 1.9 zs
Spin1/2
Quadrupole Moment
0
Discovery Year1993
Parity+

Decay ModeIntensity
p (proton emission)100%

30Cl

Mass Number30
Neutron Number13
Relative Atomic Mass
30.005018333 ± 0.000025631 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
Spin3
Quadrupole Moment
Discovery Year2018
Parity+

Decay ModeIntensity
p (proton emission)100%

31Cl

Mass Number31
Neutron Number14
Relative Atomic Mass
30.992448097 ± 0.0000037 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
190 ± 1 ms
Spin3/2
Quadrupole Moment
Discovery Year1977
Parity+

Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)2.4%

32Cl

Mass Number32
Neutron Number15
Relative Atomic Mass
31.985684605 ± 0.000000603 Da
G-Factor
1.115 ± 0.006
Abundance
Radioactivity☢️ Radioactive
Half Life
298 ± 1 ms
Spin1
Quadrupole Moment
Discovery Year1953
Parity+

Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+α (β+-delayed α emission)0.054%
β+ p (β+-delayed proton emission)0.026%

33Cl

Mass Number33
Neutron Number16
Relative Atomic Mass
32.977451988 ± 0.000000419 Da
G-Factor
0.50313333333333 ± 0.0002
Abundance
Radioactivity☢️ Radioactive
Half Life
2.5038 ± 0.0022 s
Spin3/2
Quadrupole Moment
Discovery Year1940
Parity+

Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

34Cl

Mass Number34
Neutron Number17
Relative Atomic Mass
33.97376249 ± 0.000000052 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
1.5267 ± 0.0004 s
Spin0
Quadrupole Moment
0
Discovery Year1934
Parity+

Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

35Cl

Mass Number35
Neutron Number18
Relative Atomic Mass
34.968852694 ± 0.000000038 Da
G-Factor
0.5478 ± 0.000013333333333333
Abundance
75.8 ± 0.2
RadioactivityStable
Half LifeNot Radioactive ☢️
Spin3/2
Quadrupole Moment
-0.0817 ± 0.0008
Discovery Year1919
Parity+

36Cl

Mass Number36
Neutron Number19
Relative Atomic Mass
35.968306822 ± 0.000000038 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
301.3 ± 1.5 ky
Spin2
Quadrupole Moment
-0.178 ± 0.004
Discovery Year1941
Parity+

Decay ModeIntensity
β (β decay)98.1%
β+ (β+ decay; β+ = ϵ + e+)1.9%

37Cl

Mass Number37
Neutron Number20
Relative Atomic Mass
36.965902573 ± 0.000000055 Da
G-Factor
0.456 ± 0.0000066666666666667
Abundance
24.2 ± 0.2
RadioactivityStable
Half LifeNot Radioactive ☢️
Spin3/2
Quadrupole Moment
-0.0644 ± 0.0006
Discovery Year1919
Parity+

38Cl

Mass Number38
Neutron Number21
Relative Atomic Mass
37.968010408 ± 0.000000105 Da
G-Factor
1.025 ± 0.01
Abundance
Radioactivity☢️ Radioactive
Half Life
37.23 ± 0.014 m
Spin2
Quadrupole Moment
Discovery Year1940
Parity-

Decay ModeIntensity
β (β decay)100%

39Cl

Mass Number39
Neutron Number22
Relative Atomic Mass
38.968008151 ± 0.000001859 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
56.2 ± 0.6 m
Spin3/2
Quadrupole Moment
Discovery Year1949
Parity+

Decay ModeIntensity
β (β decay)100%

40Cl

Mass Number40
Neutron Number23
Relative Atomic Mass
39.970415466 ± 0.000034423 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
1.35 ± 0.03 m
Spin2
Quadrupole Moment
Discovery Year1956
Parity-

Decay ModeIntensity
β (β decay)100%

41Cl

Mass Number41
Neutron Number24
Relative Atomic Mass
40.970684525 ± 0.000073777 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
38.4 ± 0.8 s
Spin1/2
Quadrupole Moment
0
Discovery Year1971
Parity+

Decay ModeIntensity
β (β decay)100%

42Cl

Mass Number42
Neutron Number25
Relative Atomic Mass
41.973342 ± 0.000064 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
6.8 ± 0.3 s
Spin2
Quadrupole Moment
Discovery Year1971
Parity-

Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)

43Cl

Mass Number43
Neutron Number26
Relative Atomic Mass
42.9740637 ± 0.000066407 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
3.13 ± 0.09 s
Spin3/2
Quadrupole Moment
Discovery Year1976
Parity+

Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)

44Cl

Mass Number44
Neutron Number27
Relative Atomic Mass
43.978014918 ± 0.000091859 Da
G-Factor
0.2749 ± 0.0002
Abundance
Radioactivity☢️ Radioactive
Half Life
562 ± 106 ms
Spin2
Quadrupole Moment
Discovery Year1979
Parity-

Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)8%

45Cl

Mass Number45
Neutron Number28
Relative Atomic Mass
44.980394353 ± 0.000146177 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
413 ± 25 ms
Spin3/2
Quadrupole Moment
Discovery Year1979
Parity+

Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)24%

46Cl

Mass Number46
Neutron Number29
Relative Atomic Mass
45.985254926 ± 0.0001044 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
232 ± 2 ms
Spin2
Quadrupole Moment
Discovery Year1989
Parity-

Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)60%
2n (2-neutron emission)

47Cl

Mass Number47
Neutron Number30
Relative Atomic Mass
46.989715 ± 0.000215 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
101 ± 5 ms
Spin3/2
Quadrupole Moment
Discovery Year1989
Parity+

Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)3%
2n (2-neutron emission)

48Cl

Mass Number48
Neutron Number31
Relative Atomic Mass
47.995405 ± 0.000537 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
Spin
Quadrupole Moment
Discovery Year1989
Parity

Decay ModeIntensity
β (β decay)
β n (β-delayed neutron emission)
2n (2-neutron emission)

49Cl

Mass Number49
Neutron Number32
Relative Atomic Mass
49.000794 ± 0.000429 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
Spin3/2
Quadrupole Moment
Discovery Year1989
Parity+

Decay ModeIntensity
β (β decay)
β n (β-delayed neutron emission)
2n (2-neutron emission)

50Cl

Mass Number50
Neutron Number33
Relative Atomic Mass
50.008266 ± 0.000429 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
Spin
Quadrupole Moment
Discovery Year2009
Parity

Decay ModeIntensity
β (β decay)
β n (β-delayed neutron emission)
2n (2-neutron emission)

51Cl

Mass Number51
Neutron Number34
Relative Atomic Mass
51.015341 ± 0.000751 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
Spin3/2
Quadrupole Moment
Discovery Year1990
Parity+

Decay ModeIntensity
β (β decay)
β n (β-delayed neutron emission)
2n (2-neutron emission)

52Cl

Mass Number52
Neutron Number35
Relative Atomic Mass
52.024004 ± 0.000751 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
Spin
Quadrupole Moment
Discovery Year2018
Parity

Decay ModeIntensity
β (β decay)
β n (β-delayed neutron emission)
2n (2-neutron emission)
Chlorine liquid in an ampoule

History

Around 1630, chlorine was recognized as a gas by the Belgian chemist and physician Jan Baptist van Helmont. Elemental chlorine was first prepared and studied in 1774 by Swedish chemist Carl Wilhelm Scheele. By 1810, the scientific consensus was that chlorine was actually a compound that contained oxygen. In 1811, Sir Humphry Davy concluded the new gas was in fact a new element. From the Greek word chloro, greenish yellow

DiscoverersCarl Wilhelm Scheele
Discovery LocationSweden
Discovery Year1774
Etymology (Name Origin)Greek: chlôros (greenish yellow).
PronunciationKLOR-een (English)
Elemental chlorine at high concentrations is extremely dangerous and poisonous
Tree frogs have a chlorine compound in their skin that is a very powerful pain killer

Uses

Chlorine is used for producing safe drinking water. It is also extensively used in the production of paper products, dyestuffs, textiles, petroleum products, medicines, antiseptics, insecticides, food, solvents, paints, plastics, and many other consumer products. Chlorinated compounds are used mostly for sanitation, pulp bleaching, disinfectants, and textile processing. Used in water purification, bleaches, acids and many, many other compounds such as chlorofluorocarbons (CFC).

Sources

Salt (sodium chloride, NaCl) is its most common compound. Commercial quantities are produced by electrolysis of aqueous sodium chloride (seawater or brine from salt mines).

Abundance
Abundance in Earth's crust
145 mg/kg
Natural Abundance (Oceans)
19,400 mg/L
Natural Abundance (Human Body)
0.12 %
Natural Abundance (Meteor)
0.037 %
Natural Abundance (Sun)
0.0008 %
Abundance in Universe
0.0001 %

Nuclear Screening Constants

1s0.4761
2p4.0068
2s5.5696
3p10.8839
3s9.9317

Also Known As

  • Cl
  • element 17
  • 17Cl
  • bertholite

Translations

  • Italiancloro
  • Dutchchloor
  • Norwegian Bokmålklor
  • Frenchchlore
  • GermanChlor
  • Spanishcloro
  • Chinese (Traditional)
  • Afrikaanschloor
  • Amharicክሎሪን
  • AragoneseCloro
  • Arabicكلور
  • AsturianCloru
  • AzerbaijaniXlor
  • BashkirХлор
  • Belarusianхлор
  • Bulgarianхлор
  • Banglaক্লোরিন
  • BretonKlor
  • Bosnianhlor
  • Catalanclor
  • Central Kurdishکلۆر
  • CorsicanCloru
  • Czechchlor
  • ChuvashХлор
  • WelshClorin
  • Danishklor
  • Divehiކްލޮރިން
  • Greekχλώριο
  • Esperantokloro
  • Estoniankloor
  • Basquekloro
  • Persianکلر
  • Finnishkloori
  • Northern FrisianKloor
  • FriulianClôr
  • Irishclóirín
  • GalicianCloro
  • Gujaratiનીરજી
  • Manxcloreen
  • Hakka ChineseLiu̍k
  • HawaiianKolorine
  • Hebrewכלור
  • Hindiक्लोरीन
  • Fiji HindiChlorine
  • Croatianklor
  • Haitian CreoleKlò
  • Hungarianklór
  • Armenianքլոր
  • Interlinguachloro
  • Indonesianklorin
  • Idokloro
  • Icelandicklór
  • Japanese塩素
  • Lojbankliru
  • JavaneseKlor
  • Georgianქლორი
  • KazakhХлор
  • Kannadaಕ್ಲೋರಿನ್
  • Korean염소
  • KomiХлор
  • Latinchlorum
  • LuxembourgishChlor
  • LigurianCloro
  • LingalaKoloki
  • Lithuanianchloras
  • Latvianhlors
  • Māorihau māota
  • MacedonianХлор
  • Malayalamക്ലോറിൻ
  • Marathiक्लोरिन
  • Western MariХлор
  • MalayKlorin
  • Burmeseကလိုရင်း
  • Low GermanChlor
  • Nepaliक्लोरिन
  • Norwegian Nynorskklor
  • Novialklore
  • Occitanclòr
  • Punjabiਕਲੋਰੀਨ
  • Polishchlor
  • Western Panjabiکلورین
  • Portuguesecloro
  • QuechuaKluru
  • Romanianclor
  • Russianхлор
  • Serbo-CroatianHlor
  • Sinhalaක්ලෝරීන්
  • Slovakchlór
  • Slovenianklor
  • AlbanianKlori
  • Serbianхлор
  • Saterland FrisianChlor
  • Swedishklor
  • Swahilichlorini
  • Tamilகுளோரின்
  • Teluguక్లోరిన్
  • TajikХлор
  • Thaiคลอรีน
  • TagalogKloro
  • Turkishklor
  • Tatarхлор
  • Uyghurخلور گازى
  • Ukrainianхлор
  • UzbekXlor
  • VepsHlor
  • Vietnamesechlor
  • WarayCloro
  • KalmykХлор
  • Yiddishכלאר
  • YorubaKlorínì
  • Chinese
  • CebuanoKlorin
  • Odiaକ୍ଲୋରିନ
  • PiedmonteseClòr
  • Wu Chinese氯气
  • Scotschlorine
  • Chinese (China)
  • Chinese (Hong Kong SAR China)
  • Newariक्लोरिन
  • Siciliancloru
  • Cantonese
  • Min Nan ChineseIâm-sò͘
  • ErzyaХлор
  • SomaliKoloriin
  • SamogitianChluors
  • Literary Chinese
  • Belarusian (Taraskievica orthography)хлёр
  • AromanianCloru
  • Western Frisiangloar
  • LimburgishChloear
  • KyrgyzХлор
  • cdoLṳ̆k
  • FaroeseKlor
  • Scottish GaelicClòrain
  • Sanskritक्लोरिन
  • LombardCloro
  • Maltesekloru
  • Portuguese (Brazil)cloro
  • Gan Chinese
  • Paliक्लोरिन
  • azbکولور
  • Mongolianхлор
  • Bhojpuriक्लोरीन
  • Tibetanཚྭ་རླུང་།
  • SundaneseKlor
  • Lingua Franca Novacloro
  • Tatar (Cyrillic)хлор
  • kbpKlɔrɩ
  • KurdishKlorîn
  • oloHlor
  • Tuluಕ್ಲೋರಿನ್
  • hywՔղոր
  • Chinese (Taiwan)
  • ExtremaduranCloru
  • RusynХлор
  • Urduکلورین
  • Chinese (Simplified)
  • SardinianCloro
  • Moroccan Arabicكلور
  • Egyptian Arabicكلور
  • Pashtoکلورين
  • Cornishklorin
  • WalloonClôre
  • BikolKlorina
  • Manipuriꯀ꯭ꯂꯣꯔꯤꯟ
  • BalineseKlorin
  • Gandakololiini
  • Sindhiڪلورين
  • blkကလိုရဉ်း
  • ZhuangLuz
  • ZuluIChwenzi
  • Silesianchlor
  • Lower Sorbianchlor