<Table> Rubidium, Rb <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th_colspan="2"> General properties </Th> </Tr> <Tr> <Th> Pronunciation </Th> <Td> / ruːˈbɪdiəm / ​ (roo - BID - ee - əm) </Td> </Tr> <Tr> <Th> Appearance </Th> <Td> grey white </Td> </Tr> <Tr> <Th> Standard atomic weight (A) </Th> <Td> 7001854678000000000 ♠ 85.4678 (3) </Td> </Tr> <Tr> <Th_colspan="2"> Rubidium in the periodic table </Th> </Tr> <Tr> <Td_colspan="2"> <Table> <Tr> <Td> <Table> <Tr> <Td> <Table> <Tr> <Td> Hydrogen </Td> <Td_colspan="30"> </Td> <Td> Helium </Td> </Tr> <Tr> <Td> Lithium </Td> <Td> Beryllium </Td> <Td_colspan="24"> </Td> <Td> Boron </Td> <Td> Carbon </Td> <Td> Nitrogen </Td> <Td> Oxygen </Td> <Td> Fluorine </Td> <Td> Neon </Td> </Tr> <Tr> <Td> Sodium </Td> <Td> Magnesium </Td> <Td_colspan="24"> </Td> <Td> Aluminium </Td> <Td> Silicon </Td> <Td> Phosphorus </Td> <Td> Sulfur </Td> <Td> Chlorine </Td> <Td> Argon </Td> </Tr> <Tr> <Td> Potassium </Td> <Td> Calcium </Td> <Td> Scandium </Td> <Td_colspan="14"> </Td> <Td> Titanium </Td> <Td> Vanadium </Td> <Td> Chromium </Td> <Td> Manganese </Td> <Td> Iron </Td> <Td> Cobalt </Td> <Td> Nickel </Td> <Td> Copper </Td> <Td> Zinc </Td> <Td> Gallium </Td> <Td> Germanium </Td> <Td> Arsenic </Td> <Td> Selenium </Td> <Td> Bromine </Td> <Td> Krypton </Td> </Tr> <Tr> <Td> Rubidium </Td> <Td> Strontium </Td> <Td> Yttrium </Td> <Td> </Td> <Td_colspan="13"> </Td> <Td> Zirconium </Td> <Td> Niobium </Td> <Td> Molybdenum </Td> <Td> Technetium </Td> <Td> Ruthenium </Td> <Td> Rhodium </Td> <Td> Palladium </Td> <Td> Silver </Td> <Td> Cadmium </Td> <Td> Indium </Td> <Td> Tin </Td> <Td> Antimony </Td> <Td> Tellurium </Td> <Td> Iodine </Td> <Td> Xenon </Td> </Tr> <Tr> <Td> Caesium </Td> <Td> Barium </Td> <Td> Lanthanum </Td> <Td> Cerium </Td> <Td> Praseodymium </Td> <Td> Neodymium </Td> <Td> Promethium </Td> <Td> Samarium </Td> <Td> Europium </Td> <Td> Gadolinium </Td> <Td> Terbium </Td> <Td> Dysprosium </Td> <Td> Holmium </Td> <Td> Erbium </Td> <Td> Thulium </Td> <Td> Ytterbium </Td> <Td> Lutetium </Td> <Td> Hafnium </Td> <Td> Tantalum </Td> <Td> Tungsten </Td> <Td> Rhenium </Td> <Td> Osmium </Td> <Td> Iridium </Td> <Td> Platinum </Td> <Td> Gold </Td> <Td> Mercury (element) </Td> <Td> Thallium </Td> <Td> Lead </Td> <Td> Bismuth </Td> <Td> Polonium </Td> <Td> Astatine </Td> <Td> Radon </Td> </Tr> <Tr> <Td> Francium </Td> <Td> Radium </Td> <Td> Actinium </Td> <Td> Thorium </Td> <Td> Protactinium </Td> <Td> Uranium </Td> <Td> Neptunium </Td> <Td> Plutonium </Td> <Td> Americium </Td> <Td> Curium </Td> <Td> Berkelium </Td> <Td> Californium </Td> <Td> Einsteinium </Td> <Td> Fermium </Td> <Td> Mendelevium </Td> <Td> Nobelium </Td> <Td> Lawrencium </Td> <Td> Rutherfordium </Td> <Td> Dubnium </Td> <Td> Seaborgium </Td> <Td> Bohrium </Td> <Td> Hassium </Td> <Td> Meitnerium </Td> <Td> Darmstadtium </Td> <Td> Roentgenium </Td> <Td> Copernicium </Td> <Td> Nihonium </Td> <Td> Flerovium </Td> <Td> Moscovium </Td> <Td> Livermorium </Td> <Td> Tennessine </Td> <Td> Oganesson </Td> </Tr> </Table> </Td> <Td> ↑ Rb ↓ Cs </Td> </Tr> <Tr> <Td_colspan="2"> krypton ← rubidium → strontium </Td> </Tr> </Table> </Td> </Tr> </Table> </Td> </Tr> <Tr> <Th> Atomic number (Z) </Th> <Td> 37 </Td> </Tr> <Tr> <Th> Group </Th> <Td> group 1 (alkali metals) </Td> </Tr> <Tr> <Th> Period </Th> <Td> period 5 </Td> </Tr> <Tr> <Th> Element category </Th> <Td> alkali metal </Td> </Tr> <Tr> <Th> Block </Th> <Td> s - block </Td> </Tr> <Tr> <Th> Electron configuration </Th> <Td> (Kr) 5s </Td> </Tr> <Tr> <Th> Electrons per shell </Th> <Td> 2, 8, 18, 8, 1 </Td> </Tr> <Tr> <Th_colspan="2"> Physical properties </Th> </Tr> <Tr> <Th> Phase at STP </Th> <Td> solid </Td> </Tr> <Tr> <Th> Melting point </Th> <Td> 312.45 K ​ (39.30 ° C, ​ 102.74 ° F) </Td> </Tr> <Tr> <Th> Boiling point </Th> <Td> 961 K ​ (688 ° C, ​ 1270 ° F) </Td> </Tr> <Tr> <Th> Density (near r.t.) </Th> <Td> 1.532 g / cm </Td> </Tr> <Tr> <Th> when liquid (at m.p.) </Th> <Td> 1.46 g / cm </Td> </Tr> <Tr> <Th> Triple point </Th> <Td> 312.41 K, ​? kPa </Td> </Tr> <Tr> <Th> Critical point </Th> <Td> 2093 K, 16 MPa (extrapolated) </Td> </Tr> <Tr> <Th> Heat of fusion </Th> <Td> 2.19 kJ / mol </Td> </Tr> <Tr> <Th> Heat of vaporization </Th> <Td> 69 kJ / mol </Td> </Tr> <Tr> <Th> Molar heat capacity </Th> <Td> 31.060 J / (mol K) </Td> </Tr> <Tr> <Td_colspan="2"> Vapor pressure <Table> <Tr> <Th> P (Pa) </Th> <Th> </Th> <Th> 10 </Th> <Th> 100 </Th> <Th> 1 k </Th> <Th> 10 k </Th> <Th> 100 k </Th> </Tr> <Tr> <Th> at T (K) </Th> <Td> 434 </Td> <Td> 486 </Td> <Td> 552 </Td> <Td> 641 </Td> <Td> 769 </Td> <Td> 958 </Td> </Tr> </Table> </Td> </Tr> <Tr> <Th_colspan="2"> Atomic properties </Th> </Tr> <Tr> <Th> Oxidation states </Th> <Td> + 1, − 1 ​ (a strongly basic oxide) </Td> </Tr> <Tr> <Th> Electronegativity </Th> <Td> Pauling scale: 0.82 </Td> </Tr> <Tr> <Th> Ionization energies </Th> <Td> <Ul> <Li> 1st: 403 kJ / mol </Li> <Li> 2nd: 2632.1 kJ / mol </Li> <Li> 3rd: 3859.4 kJ / mol </Li> <Li> </Li> </Ul> </Td> </Tr> <Tr> <Th> Atomic radius </Th> <Td> empirical: 248 pm </Td> </Tr> <Tr> <Th> Covalent radius </Th> <Td> 220 ± 9 pm </Td> </Tr> <Tr> <Th> Van der Waals radius </Th> <Td> 303 pm </Td> </Tr> <Tr> <Td_colspan="2"> <Table> <Tr> <Td_colspan="2"> Spectral lines </Td> </Tr> </Table> </Td> </Tr> <Tr> <Th_colspan="2"> Miscellanea </Th> </Tr> <Tr> <Th> Crystal structure </Th> <Td> ​ body - centered cubic (bcc) </Td> </Tr> <Tr> <Th> Speed of sound thin rod </Th> <Td> 1300 m / s (at 20 ° C) </Td> </Tr> <Tr> <Th> Thermal expansion </Th> <Td> 90 μm / (m K) (at r.t.) </Td> </Tr> <Tr> <Th> Thermal conductivity </Th> <Td> 58.2 W / (m K) </Td> </Tr> <Tr> <Th> Electrical resistivity </Th> <Td> 128 nΩ m (at 20 ° C) </Td> </Tr> <Tr> <Th> Magnetic ordering </Th> <Td> paramagnetic </Td> </Tr> <Tr> <Th> Magnetic susceptibility </Th> <Td> + 17.0 10 cm / mol (303 K) </Td> </Tr> <Tr> <Th> Young's modulus </Th> <Td> 2.4 GPa </Td> </Tr> <Tr> <Th> Bulk modulus </Th> <Td> 2.5 GPa </Td> </Tr> <Tr> <Th> Mohs hardness </Th> <Td> 0.3 </Td> </Tr> <Tr> <Th> Brinell hardness </Th> <Td> 0.216 MPa </Td> </Tr> <Tr> <Th> CAS Number </Th> <Td> 7440 - 17 - 7 </Td> </Tr> <Tr> <Th_colspan="2"> History </Th> </Tr> <Tr> <Th> Discovery </Th> <Td> Robert Bunsen and Gustav Kirchhoff (1861) </Td> </Tr> <Tr> <Th> First isolation </Th> <Td> George de Hevesy </Td> </Tr> <Tr> <Th_colspan="2"> Main isotopes of rubidium </Th> </Tr> <Tr> <Td_colspan="2"> <Table> <Tr> <Th> Isotope </Th> <Th> Abundance </Th> <Th> Half - life (t) </Th> <Th> Decay mode </Th> <Th> Product </Th> </Tr> <Tr> <Th> Rb </Th> <Td> syn </Td> <Td> 86.2 d </Td> <Td> ε </Td> <Td> Kr </Td> </Tr> <Tr> <Td> γ </Td> <Td>--</Td> </Tr> <Tr> <Th> Rb </Th> <Td> syn </Td> <Td> 32.9 d </Td> <Td> ε </Td> <Td> Kr </Td> </Tr> <Tr> <Td> β </Td> <Td> Kr </Td> </Tr> <Tr> <Td> γ </Td> <Td>--</Td> </Tr> <Tr> <Td> β </Td> <Td> Sr </Td> </Tr> <Tr> <Th> Rb </Th> <Td> 72.17% </Td> <Td_colspan="3"> stable </Td> </Tr> <Tr> <Th> Rb </Th> <Td> syn </Td> <Td> 18.7 d </Td> <Td> β </Td> <Td> Sr </Td> </Tr> <Tr> <Td> γ </Td> <Td>--</Td> </Tr> <Tr> <Th> Rb </Th> <Td> 27.83% </Td> <Td> 4.9 × 10 y </Td> <Td> β </Td> <Td> Sr </Td> </Tr> </Table> </Td> </Tr> <Tr> <Td_colspan="2"> <Ul> <Li> view </Li> <Li> talk </Li> <Li> </Li> </Ul> references in Wikidata </Td> </Tr> </Table> <Tr> <Th_colspan="2"> General properties </Th> </Tr>

Where is rubidium found on the periodic table
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