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


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


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

Appearance & Characteristics:

structure: bcc: body-centered cubic color: silvery-white
uses: photocells toxicity:
hardness: 0.3 mohs characteristics: soft


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

Other Forms:

number of isotopes: 2 hydride(s): RbH
oxide(s): Rb2O chloride(s): RbCl


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


thermal conductivity: 58.2 J/m-sec-deg
electrical conductivity: 77.9 1/mohm-cm polarizability: 47.3 A^3


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