Chlorine

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Chlorine Quick Reference

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Notes

Symbol

Cl

Atomic Number

17

Atomic Weight

Rounded

35.45

for regular calculations

Standard

35.446 to 35.457

for precise calculations

Oxidation States

 7

less common with disagreement

 6

less common

 5

less common with disagreement

 4

less common

 3

less common with disagreement

 2

less common

 1

less common with disagreement

 0

less common

-1

more common

Pauling Electronegativity

3.16

Electron Configuration

Orbital Occupancy

[Ne] 3s2 3p5

[Ne] represents the closed-shell electron configuration of neon

Orbital Filling Order

[Ne] 3s2 3p5

[Ne] represents the closed-shell electron configuration of neon

Term Symbol

2P3/2

see expanded configuration ...

Ionization Energies

I   (1)

12.96763 eV

II  (2)

23.8136 eV 

III (3)

39.61 eV   

IV  (4)

53.4652 eV 

see all 17 energies ...

Electron Affinity

3.612724 ± 0.000027 eV

29138.59 ± 0.22 cm-1  

Density

gas

25 °C, 1 atm

2.898 g/L 

273.15 K, 1 atm

3.164 g/L 

liquid, 172.12 K

1.723 g/ml

solid, 93 K

2.03 g/cm3

Molar Volume

gas, 273.15 K, 1 atm

22.4129 L/mol

Melting Point

1 atm

172.12 K

Boiling Point

1 atm

239.11 K

Thermal Conductivity

gas

400 K, 1 atm

0.0124 W/(m K)

300 K, 1 atm

0.0089 W/(m K)

290 K, 1 atm

0.0085 W/(m K)

280 K, 1 atm

0.0082 W/(m K)

270 K, 1 atm

0.0078 W/(m K)

see all 38 conductivities ...

Pyykkö Covalent Radius

single bond

99 pm

double bond

95 pm

triple bond

93 pm

Atomic Radius

99 pm

Enthalpy of Fusion

1 atm

6.41 kJ/mol

Enthalpy of Vaporization

1 atm

20.403 kJ/mol

Quantity

Chlorine Atomic Structure

Notes

Ionization Energies

I   (1)

12.96763 eV

II  (2)

23.8136 eV 

III (3)

39.61 eV   

IV  (4)

53.4652 eV 

see all 17 energies ...

Electron Affinity

3.612724 ± 0.000027 eV

29138.59 ± 0.22 cm-1  

Electron Binding Energies

K    (1s)

2822.4 eV

LI   (2s)

 270 eV  

LII  (2p1/2)

 202 eV  

LIII (2p3/2)

 200 eV  

Electron Configuration

Orbital Occupancy

[Ne] 3s2 3p5

[Ne] represents the closed-shell electron configuration of neon

Orbital Filling Order

[Ne] 3s2 3p5

[Ne] represents the closed-shell electron configuration of neon

Term Symbol

2P3/2

see expanded configuration ...

Clementi-Raimondi Effective Nuclear Charge

1s

Orbital Exponent

16.5239

ζ

Principle Quantum Number

1

n

Effective Nuclear Charge

16.5239

Zeff = ζ × n

2s

Orbital Exponent

 5.7152

ζ

Principle Quantum Number

2

n

Effective Nuclear Charge

11.430 

Zeff = ζ × n

see all 5 effective nuclear charges ...

Screening Percentage

64.1%

Fluorescence Yields

ωK

0.099  

ωL1

0.00012

ωL2

0.00024

ωL3

0.00024

Coster-Kronig Yields

F12

0.32

F13

0.62

Quantity

Chlorine Physical Properties

Notes

Density

gas

25 °C, 1 atm

2.898 g/L 

273.15 K, 1 atm

3.164 g/L 

liquid, 172.12 K

1.723 g/ml

solid, 93 K

2.03 g/cm3

Molar Mass

Rounded

35.45 g/mol

for regular calculations

Standard

35.446 g/mol to 35.457 g/mol

for precise calculations

Molar Volume

gas, 273.15 K, 1 atm

22.4129 L/mol

Physical Form

green-yellow gas

Speed of Sound

gas

400.00 K, 106.64 kPa

246.982 m/s

300.00 K, 138.32 kPa

213.747 m/s

290.01 K, 96.43 kPa

210.809 m/s

270.00 K, 102.60 kPa

203.272 m/s

260.00 K, 115.51 kPa

199.149 m/s

see all 54 speeds of sound ...

Dielectric Constant

liquid

2.0 

142 °F

1.5 

32 °F

2.0 

-50 °F

2.1 

208 K

2.15

Gram Atomic Volume

19 cm3

Quantity

Chlorine Atomic Interaction

Notes

Oxidation States

 7

less common with disagreement

 6

less common

 5

less common with disagreement

 4

less common

 3

less common with disagreement

 2

less common

 1

less common with disagreement

 0

less common

-1

more common

Pauling Electronegativity

3.16

Mulliken-Jaffe Electronegativity

hybrid14.3% s

3.10

orbitalp

2.76

Sanderson Electronegativity

3.475

Allred-Rochow Electronegativity

2.83

Configuration Energy

electron volt units

16.97 eV

Pauling units

 2.869  

Allen Electronegativity

2.869

Allred Electronegativity

oxidation state: 1

3.16

Boyd-Edgecombe Electronegativity

3.05

Ghosh-Gupta Electronegativity

7.2923 eV

Nagle Electronegativity

2.82

Pearson Absolute Electronegativity

8.30 eV

Smith Electronegativity

oxidation state: 1

2.9

oxidation state: -1

3.1

Chemical Hardness

4.68 eV

Cohesive Energy

per mole

135 kJ/mol    

per atom

  1.40 eV/atom

Quantity

Chlorine Thermodynamics

Notes

Melting Point

1 atm

172.12 K

Boiling Point

1 atm

239.11 K

Thermal Conductivity

gas

400 K, 1 atm

0.0124 W/(m K)

300 K, 1 atm

0.0089 W/(m K)

290 K, 1 atm

0.0085 W/(m K)

280 K, 1 atm

0.0082 W/(m K)

270 K, 1 atm

0.0078 W/(m K)

see all 38 conductivities ...

Triple Point

temperature

172.17 ± 0.05 K

pressure

0.01374 atm

Critical Point

temperature

416.956 K

pressure

7.9914 MPa

Vapor Pressure

-34.2 °C

100 kPa

-76.1 °C

10 kPa

-103.6 °C

1 kPa

see all 16 pressures ...

Enthalpy of Fusion

1 atm

6.41 kJ/mol

Enthalpy of Vaporization

1 atm

20.403 kJ/mol

Isobaric Molar Heat Capacity

298.15 K, 1 bar

33.949 J/(mol K)

Isobaric Specific Heat Capacity

298.15 K, 1 bar

0.479 J/(g K)

Quantity

Chlorine Identification

Notes

CAS Number

7782-50-5

DOT Number

1017

ICSC Number

0126

RTECS Number

FO2100000

UN Number

1017

Quantity

Chlorine Atomic Size

Notes

Atomic Radius

99 pm

Orbital Radius

72.5 pm

Pyykkö Covalent Radius

single bond

99 pm

double bond

95 pm

triple bond

93 pm

Cordero Covalent Radius

102 pm

Shannon-Prewitt Crystal Radius

ion charge: -1, coordination number: 6

167 pm

ion charge: +5, coordination number: 3, pyramidal

 26 pm

ion charge: +7

coordination number: 4

 22 pm

coordination number: 6

 41 pm

Shannon-Prewitt Effective Ionic Radius

ion charge: -1, coordination number: 6

181 pm

ion charge: +5, coordination number: 3, pyramidal

 12 pm

ion charge: +7

coordination number: 4

  8 pm

coordination number: 6

 27 pm

Pauling Empirical Crystal Radius

ion charge: -1

181 pm

Pauling Univalent Radius

ion charge: +1

 49 pm

ion charge: -1

181 pm

Batsanov Crystallographic Van Der Waals Radius

1.8×102 pm

Batsanov Equilibrium Van Der Waals Radius

205 pm

Bondi Van Der Waals Radius

175 pm

Pauling Van Der Waals Radius

180 pm

Slater Atomic-Ionic Radius

100 pm

Quantity

Chlorine Crystal Structure

Notes

Nearest Neighbor Distance

93 K, 1 atm

202 pm

Quantity

Chlorine History

Notes

Discovery

date of discovery

1774

discoverer

Carl Wilhelm Scheele

birth

December 9 (or 19), 1742

death

May 21, 1786

location of discovery

Uppsala, Sweden

Origin of Element Name

origin

khloros

origin description

color—Greek for yellow green

Origin of Element Symbol

symbol: Cl

origin

chlorine

origin description

element name

U.S. Towns Named After Elements

Chloride, Arizona

Chloride, New Mexico

Formerly Used or Proposed Element Names and Symbols

name

muriaticum

matching symbol

M

Quantity

Chlorine Abundances

Notes

Earth's Crust

1.45×102 ppm

Earth's Mantle

30 ppm

primitive mantle

Earth's Core

200 ppm

Bulk Earth

76 ppm

Ocean Water

1.987×104 ppm

River Water

8 ppm

U.S. Coal

614 ppm

Human Body

95 g

based on a 70 kg "reference man"

Human Bone

900 ppm

Human Hair

1×103 ppm to 4.8×103 ppm

Human Kidney

12×103 ppm

Human Liver

3×103 ppm to 7.2×103 ppm

Human Muscle

2×103 ppm to 5.2×103 ppm

Human Nail

1×103 ppm to 3.6×103 ppm

Bacteria

2300 ppm

Ferns

6×103 ppm

Fungi

10000 ppm

Solar System

5240

number of atoms for every 106 atoms of silicon

Sun

5.5 ± 0.3

base 10 log of the number of atoms for every 1012 atoms of hydrogen

Meteorites

5.26 ± 0.06

base 10 log of the number of atoms for every 1012 atoms of hydrogen

Quantity

Chlorine Nomenclature

Notes

Element Names in Other Languages

French

chlore

German

Chlor

Italian

cloro

Spanish

cloro

Portuguese

cloro

Anions or Anionic Substituent Groups

chloride (general)

Cl-, chloride(1-)

Cations or Cationic Substituent Groups

chlorine (general)

Cl+, chlorine(1+)

Ligands

chlorido (general)

Cl-, chlorido(1-)

Heteroatomic Anion

chlorate

'a' Term—Substitutive Nomenclature

chlora

'y' Term—Chains and Rings Nomenclature

chlory

References    (Click the button next to a value above to see complete citation information for that entry)

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