Rubidium Elemental Symbol (Rb)
Rubidium



French German Italian Portuguese Spanish Swedish
Rubidium Rubidium Rubidio Rubídio Rubidio Rubidium

Rubidium(Rb) atomic and molecular weight, atomic number and elemental symbol Rubidium is a Block S, Group 1, Period 5 element. Rubidium Bohr ModelThe number of electrons in each of Rubidium's shells is 2, 8, 18, 8, 1 and its electronic configuration is [Kr] 5s1. The rubidium atom has a radius of 247.5.pm and a Van der Waals radius of 200.pm. Rubidium is highly reactive, with properties similar to other Group 1 elements, e.g., rapid oxidation in air. In its elemental form, CAS 7440-17-7, rubidium has a gray white appearance. Rubidium is found in the minerals lepidolite, leucite, pollucite, carnallite, and zinnwaldite as well as some potassium minerals. Rubidium was first discovered by Robert Bunsen and Gustav Kirchhoff in 1861. The name Rubidium, originates from the Latin word rubidus, which means dark or deepest red.

Rubidium has various applications in medicine and photo-electronics. High Purity (99.999%) Rubidium Oxide (Rb2O) Powder Since it is easily vaporized, rubidium's spectral absorption range is a good target for laser manipulation of atoms. Rubidium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Nanoparticles and nanopowders provide ultra-high surface area which nanotechnology research and recent experiments demonstrate function to create new and unique properties and benefits. Oxides are available in forms including powders and dense pellets for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Rubidium is available in soluble forms including chlorides, nitrates and acetates. These compounds are also manufactured as solutions at specified stoichiometries.

Safety data for rubidium compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab below.


  • Properties
  • Safety Data
  • Products
  • Research
  • Isotopes
  • Other Elements

Rubidium Properties


GENERAL PROPERTIES   PHYSICAL PROPERTIES  
Symbol: Rb Melting Point: 312.46 K, 39.31 °C, 102.76 °F
Atomic Number: 37 Boiling Point: 961 K, 688 °C, 1270 °F
Atomic Weight: 85.4678 Density: 1.532 g·cm−3
Element Category: alkali metal Liquid Density @ Melting Point: 1.46 g·cm−3
Group, Period, Block: 1, 5, s Specific Heat: 0.363J/gK
    Heat of Vaporization 75.7 kJ mol-1
CHEMICAL STRUCTURE Heat of Fusion 2.2 kJ mol-1
Electrons: 37 Thermal Conductivity: 58.2 W·m−1·K−1
Protons: 37 Thermal Expansion: N/A
Neutrons: 48 Electrical Resistivity: (20 °C) 128 nΩ·m
Electron Configuration: [Kr] 5s1 2, 8, 18, 8, 1 Electronegativity: 0.82 (Pauling scale)
Atomic Radius: 248 pm Tensile Strength: N/A
Covalent Radius: 220±9 pm Molar Heat Capacity: 31.060 J·mol−1·K−1
Van der Waals radius: 303 pm Young's Modulus: 2.4 GPa
Oxidation States: 1 (strongly basic oxide) Shear Modulus: N/A
Phase: Solid Bulk Modulus: 2.5 GPa
Crystal Structure: body-centered cubic Poisson Ratio: N/A
Magnetic Ordering: paramagnetic Mohs Hardness: 0.3
1st Ionization Energy: 403.03 kJ mol-1 Vickers Hardness: N/A
2nd Ionization Energy: 2632.62 kJ mol-1 Brinell Hardness: 0.216 MPa
3rd Ionization Energy: 3859.44 kJ mol-1 Speed of Sound: (20 °C) 1300 m·s−1
       
IDENTIFIERS   MISCELLANEOUS  
CAS Number: 7440-17-7 Abundance in typical human body, by weight: 4600 ppb
ChemSpider ID: 4512975 Abundance in typical human body, by atom: 340 ppb
PubChem CID: 5357696 Abundance in universe, by weight: 10 ppb
MDL Number: MFCD00134055 Abundance in universe, by atom: 0.1 ppb
EC Number: 231-126-6 Discovered By: Robert Bunsen and Gustav Kirchhoff
Beilstein Number: N/A Discovery Date: 1861
SMILES Identifier: [Rb]  
InChI Identifier: InChI=1S/Rb Other Names: Rubidij, Rubidio
InChI Key: IGLNJRXAVVLDKE-UHFFFAOYSA-N  
       
       
       
       
       


Recent Research & Development for Rubidium

  • High-temperature phase transitions, spectroscopic properties, and dimensionality reduction in rubidium thorium molybdate family. Xiao B, Gesing TM, Kegler P, Modolo G, Bosbach D, Schlenz H, Suleimanov EV, Alekseev EV. Inorg Chem. 2014
  • Relations of bromine, iron, rubidium, strontium, and zinc content to morphometric parameters in pediatric and nonhyperplastic young adult prostate glands. Zaichick V, Zaichick S. Biol Trace Elem Res. 2014.
  • Insights into Gas-Phase Structural Conformers of Hydrated Rubidium and Cesium Cations, M+(H2O)nAr (M = Rb, Cs; n = 3-5), Using Infrared Photodissociation Spectroscopy. Ke H, van der Linde C, Lisy JM. J Phys Chem A. 2014 Feb.
  • Observing and preventing rubidium runaway in a direct-infusion xenon-spin hyperpolarizer optimized for high-resolution hyper-CEST (chemical exchange saturation transfer using hyperpolarized nuclei) NMR. Witte C, Kunth M, Rossella F, Schröder L. J Chem Phys. 2014
  • Relations of Bromine, Iron, Rubidium, Strontium, and Zinc Content to Morphometric Parameters in Pediatric and Nonhyperplastic Young Adult Prostate Glands. Zaichick V, Zaichick S. Biol Trace Elem Res. 2014 Jan.
  • Explorations of New Second-Order Nonlinear Optical Materials in the Ternary Rubidium Iodate System: Noncentrosymmetric ß-RbIO3(HIO3)2 and Centrosymmetric Rb3(IO3)3(I2O5)(HIO3)4(H2O). Xu X, Yang BP, Huang C, Mao JG. Inorg Chem. 2014 Feb.
  • Special K: testing the potassium link between radioactive rubidium (86Rb) turnover and metabolic rate. Tomlinson S, Mathialagan PD, Maloney SK. J Exp Biol. 2013 Dec.
  • Impact of point spread function modeling and time-of-flight on myocardial blood flow and myocardial flow reserve measurements for rubidium-82 cardiac PET. Armstrong IS, Tonge CM, Arumugam P. J Nucl Cardiol. 2014 Jan.
  • Explorations of New Second-Order Nonlinear Optical Materials in the Ternary Rubidium Iodate System: Noncentrosymmetric ß-RbIO3(HIO3)2 and Centrosymmetric Rb3(IO3)3(I2O5)(HIO3)4(H2O). Xu X, Yang BP, Huang C, Mao JG. Inorg Chem. 2014 Jan.
  • Collective librations of water molecules in the crystal lattice of rubidium bromide: experiment and simulation. Lepodise LM, Horvat J, Lewis RA. Phys Chem Chem Phys. 2013 Dec.
  • Clinical Interpretation Standards and Quality Assurance for the Multicenter PET/CT Trial Rubidium-ARMI. Renaud JM, Mylonas I, McArdle B, Dowsley T, Yip K, Turcotte E, Guimond J, Trottier M, Pibarot P, Maguire C, Lalonde L, Gulenchyn K, Wisenberg G, Wells RG, Ruddy T, Chow B, Beanlands RS, Dekemp RA. J Nucl Med. 2014 Jan.
  • Collective librations of water molecules in the crystal lattice of rubidium bromide: experiment and simulation. Phys Chem Chem Phys. | first author:Lepodise LM
  • Ultralow frequency Stokes and anti-Stokes Raman spectroscopy of single living cells and microparticles using a hot rubidium vapor filter. Lin J, Li YQ. Opt Lett. 2014 Jan.
  • Added prognostic value of myocardial blood flow quantitation in rubidium-82 positron emission tomography imaging. Farhad H, Dunet V, Bachelard K, Allenbach G, Kaufmann PA, Prior JO. Eur Heart J Cardiovasc Imaging. 2013 Dec.
  • Feasibility of stress only rubidium-82 PET myocardial perfusion imaging. J Nucl Cardiol. 2013 | first author:McMahon SR
  • Encapsulation of ammonium molybdophosphate and zirconium phosphate in alginate matrix for the sorption of rubidium(I). J Colloid Interface Sci. 2013 create date:2013/09/03 | first author:Krys P
  • Encapsulation of ammonium molybdophosphate and zirconium phosphate in alginate matrix for the sorption of rubidium(I). J Colloid Interface Sci. 2013 create date:2013/09/03 | first author:Krys P
  • Probing of local structures of thermal and photoinduced phases in rubidium manganese hexacyanoferrate by resonant Raman spectroscopy. J Chem Phys. | first author:Fukaya R
  • Review: comparison of PET rubidium-82 with conventional SPECT myocardial perfusion imaging. Clin Physiol Funct Imaging. 2013 | first author:Ghotbi AA
  • Atom-based vector microwave electrometry using rubidium Rydberg atoms in a vapor cell. Phys Rev Lett. 2013 | first author:Sedlacek JA

Rubidium Isotopes


Rubidium (Rb) has 32 isotopes, two of which are naturally occurring: 85Rb (72.2%) and the radioactive 87Rb (27.8%).

Nuclide Symbol Isotopic Mass Half-Life Nuclear Spin
85Rb 84.911789738 Stable 5/2-
87Rb 86.909180527 4.923(22)×1010 a 3/2-