General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Chlorine Symbol Cl
atomic number 17 Atomic weight 35.453
Density @ 293 K 0.003214 g/cm3 Atomic volume 22.7 cm3/mol
Group Halogen discovered 1774


state (s, l, g) g
melting point 172.22 K boiling point 239.2 K
Heat of fusion 3.203 kJ/mol Heat of vaporization 10.20 kJ/mol
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1st ionization energy 1251.1 kJ/mole electronegativity 3.16
2nd ionization energy 2297.3 kJ/mole electron affinity 349 kJ/mole
3rd ionization energy 3821.8 kJ/mole Specific heat 0.48 J/gK
heat atomization 121 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,7 electron configuration [Ne] 3s2 3p5
minimum oxidation number -1 maximum oxidation number 7
min. common oxidation no. -1 max. common oxidation no. 7
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Appearance & Characteristics

structure layers of Cl2 color greenish-yellow
uses bleach (NaOCl), PVC pipe toxicity yes
hardness mohs characteristics diatomic(Cl2), corrosive


reaction with air none reaction with 6M HCl mild, = HOCl, Cl-
reaction with 6M HCl mild, = HOCl, Cl- reaction with 15M HNO3 mild, = HClOx, NOxCl, NOx
reaction with 6M NaOH mild, = OCl-, Cl-
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Other Forms

number of isotopes 2 hydride(s) HCl
oxide(s) Cl2O ClO2 Cl2O7 chloride(s) Cl2


ionic radius (2- ion) pm ionic radius (1- ion) 167 pm
atomic radius 100 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) pm
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thermal conductivity 0.01 J/m-sec-deg electrical conductivity 0 1/mohm-cm
polarizability 2.2 A^3


source Halite, brine (misc) rel. abund. solar system 3.719 log
abundance earth's crust 2.1 log cost, pure 0.15 $/100g
cost, bulk $/100g
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World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.