Chemicool

Cs

55

132.9054
Cesium
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General

Name Cesium Symbol Cs
atomic number 55 Atomic weight 132.9054
Density @ 293 K 1.873 g/cm3 Atomic volume 71.07 cm3/mol
Group Alkali Met. discovered 1860

States

state (s, l, g) s
melting point 301.6 K boiling point 978 K
Heat of fusion 2.092 kJ/mol Heat of vaporization 67.740 kJ/mol
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Energies

1st ionization energy 375.7 kJ/mole electronegativity 0.79
2nd ionization energy 2421.8 kJ/mole electron affinity 45.506 kJ/mole
3rd ionization energy kJ/mole Specific heat 0.24 J/gK
heat atomization 79 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,18,8,1 electron configuration [Xe] 6s1
minimum oxidation number 0 maximum oxidation number 1
min. common oxidation no. 0 max. common oxidation no. 1
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Appearance & Characteristics

structure bcc: body-centered cubic color yellow/silvery
uses photocells, IR lamps toxicity
hardness 0.2 mohs characteristics softest metal

Reactions

reaction with air vigorous, = CsO2 reaction with 6M HCl vigorous, = H2, CsCl
reaction with 6M HCl vigorous, = H2, CsCl reaction with 15M HNO3 vigorous, = CsNO3
reaction with 6M NaOH vigorous, = H2, CsOH
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Other Forms

number of isotopes 1 hydride(s) CsH
oxide(s) Cs2O chloride(s) CsCl

Radius

ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 265 pm ionic radius (1+ ion) 181 pm
ionic radius (2+ ion) pm ionic radius (3+ ion) pm
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Conductivity

thermal conductivity 35.9 J/m-sec-deg electrical conductivity 48.9 1/mohm-cm
polarizability 59.6 A^3

Abundance

source Li extractn by-product rel. abund. solar system -0.429 log
abundance earth's crust 0 log cost, pure 1100 $/100g
cost, bulk $/100g
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