• Class: Alkalis
• Period: 5
• IUPAC group: 1
• Traditional: Ia

• Discovered in: 1861 by Bunsen, Kirchhoff
• Origin of name: Latin: rubidius, (deepest red)
• Historical or alternate name:

Pollucite, carnallite, leucite, zinnwaldite & Potassium minerals

Very soft metal. Lustrous, silvery white when surface is freshly exposed. Ignites in air; violently reacts with water.

• Atmosphere: ~0.0 ppm
• Primitive mantle: 0.55 ppm
• Sea water: 0.12 ppm
• Metallic meteorite: 2.30 ppm
• Continental crust: 32.0 ppm
• Solar photosphere: 2.60 log of abundance
• Oceanic crust: 2.2 ppm
• Solar system: 7.09 relative to Si=1.0e6

   Hazards

Highly flammable. Ignites in air. Reacts violently with water or oxidants..

• Lower:1.0
• Upper:100.0

Rubidium Physical Properties

 Transitional Data

• State: Solid
• Density: 1.532 g/cm3

 Molar enthalpy

• Atomization: 82.17 kJ mol-1
• Fusion: 2.20 kJ mol-1
• Vaporization: 75.7 kJ mol-1

 Transition points

• Melting point: 312.04 K
• Boiling point: 959.0 K
• Critical temperature: 2093.0 K

 Molar properties

• Atomic weight: 85.4678 g/mole
• Molar volume: 56.200 cm3 mol-1

 Crystal structure sequence

body-centered-cubic

 Thermodynamics

• State: solid
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 76.78
  • Heat Capacity 31.062

• State: gas
  • Enthalpy 80.88
  • Gibbs function 53.06
  • Entropy 170.089
  • Heat Capacity 20.786

 Miscellaneous physical

• Electrical resistivity: 12.5 µ-ohms/cm
• Debye temperature: 56.0 K
• Thermal conductivity: 52.8 W / m / K
• Coefficient of linear expansion: 90.0Coef. per K
• Mass magnetic susceptibility: 2.49e-9
• X-ray diffraction mass absorption coefficients:
• CuK: 117 (µ/p)/cm2 g-1
• MoK: 90.0 (µ/p)/cm2 g-1

Rubidium Chemical Properties

 Chemical basics:

• Oxidation states: +1
• Molecular wt: 85.4678 g/mole

 Radii

• Covalent: pm
• Atomic: 250.0 pm
• Van der Waals: 244 pm

 Ions:

• ion: +1 pm 152.0

 Covalent bonds

 Effective nuclear charge

• Slater: 2.20
• Clementi: 4.98
• Froese-Fischer: 6.66

 Electronegativity

• Pauling: 0.8
• Allred-Rochow: 0.89

 Standard reactions

Rubidium Nuclear Properties

• Known 20
• Listed 5

• Known 79 - 95
• Listed 83 - 87

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 86.2 days
  • Decay mode: E.C.,
  • Source: reactor
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 32.8 days
  • Decay mode: E.C., Beta+ Beta-
  • Source: reactor
• Notes med

• % Occ.:Natural 72.165%
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 5/2
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 18.7 days
  • Decay mode: Beta- E.C.,
  • Source: reactor
• Notes med

• % Occ.:Natural 27.875%
• Mossbauer NRA:
• Nuclear spin/Quantum no.: 3/2
• Radioisotopes:
  • Half-life: 48.8 E9 years
  • Decay mode: Beta-
  • Source: reactor
• Notes date

• Isotope Cross-section 0.5±0.1 barns

• Absolute sensitivity: 7.57e-3 1H=1.0
• Relative sensitivity: 1.05e-2 1H=1.0
• Receptivity: 43 13C=1.0
• Magnetogyric ratio: 2.5828e7 rad / T / s
• Quadropole moment: 0.25e-28 m2
• Frequency: 9.655 MHz
• Reference: RbCl

Rubidium Energy Properties

Electrons

• Ground state electron configuration: [Kr] 5s1
• Electron affinity: 46.9 kJ mol-1
• Filling orbitals:

Spectral lines

 Ionization energies

 Atomic energy levels