Rubidium

Rubidium Element Properties

p36
Kr
Krypton
s37
Rb
Rubidium
s38
Sr
Strontium
General
NameRubidium
SymbolRb
Number37
Group Number1
GroupAlkali metals
Blocks
Density1.53 g/cm3
Atomic Weight85.467 g/mol
Atomic Volume55.9 cm3/mol
Discover1861


States
StateSolid
Melting Point312.46 K
Boiling Point961 K
Triple PointNil
Critical Point2093 K
Heat of Fusion2.19 kJ/mol
Heat of Vaporization75.77 kJ/mol


Energies
First Ionization Energy403 kJ/mole
Second Ionization Energy2632.1 kJ/mole
Third Ionization Energy3859.4 kJ/mole
Electronegativity0.82
Electron Affinity46.885 kJ/mole
Specific Heat0.363 J/gK
Heat Atomization86 kJ/mole atoms


Oxidation and Electrons
Shells2,8,18,8,1
Electron Configuration[Kr] 5s1
Minimum Oxidation Number0
Maximum Oxidation Number1
Minimum Common Oxidation Number0
Maximum Common Oxidation Number1


Appearance and Characteristics
Crystal Structurecubic body centered
Characteristicssoft
Colorsilvery-white
Usesphotocells
Hardness0.3 mohs
ToxicityNone


Reactions
Reaction with Airvigorous, =>RbO2
Reaction with 6M HClvigorous, =>H2, RbCl
Reaction with 15M HNO3vigorous,=>RbNO3, H2, NOx
Reaction with 6M NaOHvigorous, =>H2, RbOH


Other Forms
Number of Isotopes2
HydrideRbH
OxideRb2O
ChlorideRbCl


Radius
Atomic Radius248 pm
Ionic Radius (1+ ion)166 pm
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)Nil
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)Nil


Conductivity
Thermal Conductivity58.2 J/m-sec-deg
Electrical Conductivity77.9 1/mohm-cm
Polarizability47.3 A3


Abundance
SourceLi extractn by-product
Relation Abundance Solar System0.851 log
Abundance Earth's Crust2 log


p36
Kr
Krypton
s37
Rb
Rubidium
s38
Sr
Strontium