Rubidium

Rubidium, ₃₇Rb
Rubidium
Pronunciation	/ruːˈbɪdiəm/ (roo-BID-ee-əm)
Appearance	grey white
Standard atomic weight Ar, std(Rb)	85.4678(3)
Rubidium in the periodic cairt
	krypton ← rubidium → strontium
Atomic nummer (Z)	37
Group	group 1 (alkali metals)
Period	period 5
Block	s-block
Element category	Alkali metal
Electron confeeguration	[Kr] 5s1
Electrons per shell	2, 8, 18, 8, 1
Pheesical properties
Phase at STP	solit
Meltin pynt	312.45 K (39.30 °C, 102.74 °F)
Bylin pynt	961 K (688 °C, 1270 °F)
Density (near r.t.)	1.532 g/cm3
when liquid (at m.p.)	1.46 g/cm3
Treeple pynt	312.41 K, ? kPa
Creetical pynt	2093 K, 16 MPa (extrapolatit)
Heat o fusion	2.19 kJ/mol
Heat o vapourisation	69 kJ/mol
Molar heat capacity	31.060 J/(mol·K)
Atomic properties
Oxidation states	−1, +1 strangly basic
Electronegativity	Pauling scale: 0.82
Ionisation energies	1st: 403 kJ/mol ; 2nd: 2632.1 kJ/mol ; 3rd: 3859.4 kJ/mol ; ;
Atomic radius	empirical: 248 pm
Covalent radius	220±9 pm
Van der Waals radius	303 pm
	Colour lines in a spectral rangeSpectral lines o rubidium
Ither properties
Naitural occurrence	primordial
Creestal structur	body-centred cubic (bcc)
Speed o soond thin rod	1300 m/s (at 20 °C)
Thermal expansion	90 µm/(m·K) (at r.t.)
Thermal conductivity	58.2 W/(m·K)
Electrical resistivity	128 nΩ·m (at 20 °C)
Magnetic orderin	paramagnetic
Young's modulus	2.4 GPa
Bulk modulus	2.5 GPa
Mohs haurdness	0.3
Brinell haurdness	0.216 MPa
CAS Nummer	7440-17-7
History
Diskivery	Robert Bunsen an Gustav Kirchhoff (1861)
First isolation	George de Hevesy
Main isotopes o rubidium
γ	–
β+	84Kr
γ	–
β−	84Sr
γ	–
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Rubidium is a chemical element wi seembol Rb an atomic nummer 37. Rubidium is a saft, sillery-white metallic element o the alkali metal group, wi an atomic mass o 85.4678. Elemental rubidium is heichly reactive, wi properties seemilar tae those o ither alkali metals, sic as very rapid oxidation in air. Naitural rubidium is a mix o twa isotopes: ⁸⁵Rb, the anly stable ane, constitutes 72% o it. The remainin 28% is the slichtly radioactive ⁸⁷Rb wi a hauf-life o 49 billion year—mair nor three times langer than the estimatit age o the universe.

References

↑ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
↑ ^a ^b Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nt ed.). CRC Press. p. 4.122. ISBN 1439855110.
↑ http://www.owlnet.rice.edu/~msci301/ThermalExpansion.pdf
↑ Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
↑ Standard Atomic Weights 2013. Commission on Isotopic Abundances and Atomic Weights

[CIAAW2013-1] Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.

[b92-2] Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nt ed.). CRC Press. p. 4.122. ISBN 1439855110.

[3] ttp://www.owlnet.rice.edu/~msci301/ThermalExpansion.pdf

[magnet-4] Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.

[IUPAC-5] Standard Atomic Weights 2013. Commission on Isotopic Abundances and Atomic Weights

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