Rubidium

  • rubidium, 37rb
    rb5.jpg
    rubidium
    pronunciationm/ (bid-ee-əm)
    appearancegrey white
    standard atomic weight ar, std(rb)85.4678(3)[1]
    rubidium in the periodic table
    hydrogen helium
    lithium beryllium boron carbon nitrogen oxygen fluorine neon
    sodium magnesium aluminium silicon phosphorus sulfur chlorine argon
    potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton
    rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon
    caesium barium lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury (element) thallium lead bismuth polonium astatine radon
    francium radium actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson
    k

    rb

    cs
    kryptonrubidiumstrontium
    atomic number (z)37
    groupgroup 1: h and alkali metals
    periodperiod 5
    blocks-block
    element category  alkali metal
    electron configuration[kr] 5s1
    electrons per shell2, 8, 18, 8, 1
    physical properties
    phase at stpsolid
    melting point312.45 k ​(39.30 °c, ​102.74 °f)
    boiling point961 k ​(688 °c, ​1270 °f)
    density (near r.t.)1.532 g/cm3
    when liquid (at m.p.)1.46 g/cm3
    triple point312.41 k, ​? kpa[2]
    critical point2093 k, 16 mpa (extrapolated)[2]
    heat of fusion2.19 kj/mol
    heat of vaporization69 kj/mol
    molar heat capacity31.060 j/(mol·k)
    vapor pressure
    p (pa) 1 10 100 1 k 10 k 100 k
    at t (k) 434 486 552 641 769 958
    atomic properties
    oxidation states−1, +1 (a strongly basic oxide)
    electronegativitypauling scale: 0.82
    ionization energies
    • 1st: 403 kj/mol
    • 2nd: 2632.1 kj/mol
    • 3rd: 3859.4 kj/mol
    atomic radiusempirical: 248 pm
    covalent radius220±9 pm
    van der waals radius303 pm
    color lines in a spectral range
    spectral lines of rubidium
    other properties
    natural occurrenceprimordial
    crystal structurebody-centered cubic (bcc)
    body-centered cubic crystal structure for rubidium
    speed of sound thin rod1300 m/s (at 20 °c)
    thermal expansion90 µm/(m·k)[3] (at r.t.)
    thermal conductivity58.2 w/(m·k)
    electrical resistivity128 nΩ·m (at 20 °c)
    magnetic orderingparamagnetic[4]
    magnetic susceptibility+17.0·10−6 cm3/mol (303 k)[5]
    young's modulus2.4 gpa
    bulk modulus2.5 gpa
    mohs hardness0.3
    brinell hardness0.216 mpa
    cas number7440-17-7
    history
    discoveryrobert bunsen and gustav kirchhoff (1861)
    first isolationgeorge de hevesy
    main isotopes of rubidium
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    83rb syn 86.2 d ε 83kr
    γ
    84rb syn 32.9 d ε 84kr
    β+ 84kr
    γ
    β 84sr
    85rb 72.17% stable
    86rb syn 18.7 d β 86sr
    γ
    87rb 27.83% 4.9×1010 y β 87sr
    category category: rubidium
    | references

    rubidium is a chemical element with the symbol rb and atomic number 37. rubidium is a very soft, silvery-white metal in the alkali metal group. rubidium metal shares similarities to potassium metal and caesium metal in physical appearance, softness and conductivity.[6] rubidium cannot be stored under atmospheric oxygen, as a highly exothermic reaction will ensue, sometimes even resulting in the metal catching fire.[7]

    rubidium is the first alkali metal in the group to have a density higher than water, so it sinks, unlike the metals above it in the group. rubidium has a standard atomic weight of 85.4678. on earth, natural rubidium comprises two isotopes: 72% is a stable isotope 85rb, and 28% is slightly radioactive 87rb, with a half-life of 49 billion years—more than three times as long as the estimated age of the universe.

    german chemists robert bunsen and gustav kirchhoff discovered rubidium in 1861 by the newly developed technique, flame spectroscopy. the name comes from the latin word rubidus, meaning deep red, the color of its emission spectrum. rubidium's compounds have various chemical and electronic applications. rubidium metal is easily vaporized and has a convenient spectral absorption range, making it a frequent target for laser manipulation of atoms. rubidium is not a known nutrient for any living organisms. however, rubidium ions have the same charge as potassium ions and are actively taken up and treated by animal cells in similar ways.

  • characteristics
  • production
  • history
  • applications
  • precautions and biological effects
  • see also
  • references
  • further reading
  • external links

Rubidium, 37Rb
Rb5.JPG
Rubidium
Pronunciationm/ (BID-ee-əm)
Appearancegrey white
Standard atomic weight Ar, std(Rb)85.4678(3)[1]
Rubidium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
K

Rb

Cs
kryptonrubidiumstrontium
Atomic number (Z)37
Groupgroup 1: H and alkali metals
Periodperiod 5
Blocks-block
Element category  Alkali metal
Electron configuration[Kr] 5s1
Electrons per shell2, 8, 18, 8, 1
Physical properties
Phase at STPsolid
Melting point312.45 K ​(39.30 °C, ​102.74 °F)
Boiling point961 K ​(688 °C, ​1270 °F)
Density (near r.t.)1.532 g/cm3
when liquid (at m.p.)1.46 g/cm3
Triple point312.41 K, ​? kPa[2]
Critical point2093 K, 16 MPa (extrapolated)[2]
Heat of fusion2.19 kJ/mol
Heat of vaporization69 kJ/mol
Molar heat capacity31.060 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 434 486 552 641 769 958
Atomic properties
Oxidation states−1, +1 (a strongly basic oxide)
ElectronegativityPauling scale: 0.82
Ionization energies
  • 1st: 403 kJ/mol
  • 2nd: 2632.1 kJ/mol
  • 3rd: 3859.4 kJ/mol
Atomic radiusempirical: 248 pm
Covalent radius220±9 pm
Van der Waals radius303 pm
Color lines in a spectral range
Spectral lines of rubidium
Other properties
Natural occurrenceprimordial
Crystal structurebody-centered cubic (bcc)
Body-centered cubic crystal structure for rubidium
Speed of sound thin rod1300 m/s (at 20 °C)
Thermal expansion90 µm/(m·K)[3] (at r.t.)
Thermal conductivity58.2 W/(m·K)
Electrical resistivity128 nΩ·m (at 20 °C)
Magnetic orderingparamagnetic[4]
Magnetic susceptibility+17.0·10−6 cm3/mol (303 K)[5]
Young's modulus2.4 GPa
Bulk modulus2.5 GPa
Mohs hardness0.3
Brinell hardness0.216 MPa
CAS Number7440-17-7
History
DiscoveryRobert Bunsen and Gustav Kirchhoff (1861)
First isolationGeorge de Hevesy
Main isotopes of rubidium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
83Rb syn 86.2 d ε 83Kr
γ
84Rb syn 32.9 d ε 84Kr
β+ 84Kr
γ
β 84Sr
85Rb 72.17% stable
86Rb syn 18.7 d β 86Sr
γ
87Rb 27.83% 4.9×1010 y β 87Sr
Category Category: Rubidium
| references

Rubidium is a chemical element with the symbol Rb and atomic number 37. Rubidium is a very soft, silvery-white metal in the alkali metal group. Rubidium metal shares similarities to potassium metal and caesium metal in physical appearance, softness and conductivity.[6] Rubidium cannot be stored under atmospheric oxygen, as a highly exothermic reaction will ensue, sometimes even resulting in the metal catching fire.[7]

Rubidium is the first alkali metal in the group to have a density higher than water, so it sinks, unlike the metals above it in the group. Rubidium has a standard atomic weight of 85.4678. On Earth, natural rubidium comprises two isotopes: 72% is a stable isotope 85Rb, and 28% is slightly radioactive 87Rb, with a half-life of 49 billion years—more than three times as long as the estimated age of the universe.

German chemists Robert Bunsen and Gustav Kirchhoff discovered rubidium in 1861 by the newly developed technique, flame spectroscopy. The name comes from the Latin word rubidus, meaning deep red, the color of its emission spectrum. Rubidium's compounds have various chemical and electronic applications. Rubidium metal is easily vaporized and has a convenient spectral absorption range, making it a frequent target for laser manipulation of atoms. Rubidium is not a known nutrient for any living organisms. However, rubidium ions have the same charge as potassium ions and are actively taken up and treated by animal cells in similar ways.