Chemicool

Rb

37

85.467
Rubidium
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General
Name Rubidium Symbol Rb
atomic number 37 Atomic weight 85.467
Density @ 293 K 1.53 g/cm3 Atomic volume 55.9 cm3/mol
Group Alkali Met. discovered 1861

States
state (s, l, g) s
melting point 312.09 K boiling point 961 K
Heat of fusion 2.192 kJ/mol Heat of vaporization 72.216 kJ/mol
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Energies
1st ionization energy 403 kJ/mole electronegativity 0.82
2nd ionization energy 2632.1 kJ/mole electron affinity 46.885 kJ/mole
3rd ionization energy 3859.4 kJ/mole Specific heat 0.363 J/gK
heat atomization 86 kJ/mole atoms

Oxidation & Electrons
Shells 2,8,18,8,1 electron configuration [Kr] 5s1
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 silvery-white
uses photocells toxicity
hardness 0.3 mohs characteristics soft

Reactions
reaction with air vigorous, = RbO2 reaction with 6M HCl vigorous, = H2, RbCl
reaction with 6M HCl vigorous, = H2, RbCl reaction with 15M HNO3 vigorous,= RbNO3, H2, NOx
reaction with 6M NaOH vigorous, = H2, RbOH
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Other Forms
number of isotopes 2 hydride(s) RbH
oxide(s) Rb2O chloride(s) RbCl

Radius
ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 248 pm ionic radius (1+ ion) 166 pm
ionic radius (2+ ion) pm ionic radius (3+ ion) pm
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Conductivity
thermal conductivity 58.2 J/m-sec-deg electrical conductivity 77.9 1/mohm-cm
polarizability 47.3 A^3

Abundance
source Li extractn by-product rel. abund. solar system 0.851 log
abundance earth's crust 2 log cost, pure 1200 $/100g
cost, bulk $/100g
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