Difference between revisions of "Rubidium"

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{{Infobox element
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<!-- General properties -->
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|name=Rubidium
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|symbol=Rb
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|pronounce=
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|pronounce ref=
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|pronounce comment=
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|pronounce 2=
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|alt name=
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|alt names=
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|allotropes=
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|appearance=Silvery-white
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<!-- Periodic table -->
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|above=[[Potassium|K]]
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|below=[[Caesium|Cs]]
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|left=[[Krypton]]
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|right=[[Strontium]]
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|number=37
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|atomic mass=85.4678(3)
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|atomic mass 2=
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|atomic mass ref=
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|atomic mass comment=
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|series=
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|series ref=
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|series comment=
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|series color=
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|group=1
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|group ref=
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|group comment=(alkali metals)
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|period=5
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|period ref=
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|period comment=
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|block=s
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|block ref=
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|block comment=
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|electron configuration=[Kr] 5s<sup>1</sup>
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|electron configuration ref=
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|electron configuration comment=
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|electrons per shell=2, 8, 18, 8, 1
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|electrons per shell ref=
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|electrons per shell comment=
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<!-- Physical properties -->
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|physical properties comment=
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|color=Silvery-white
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|phase=Solid
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|phase ref=
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|phase comment=
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|melting point K=312.45
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|melting point C=39.30
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|melting point F=​102.74
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|melting point ref=
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|melting point comment=
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|boiling point K=961
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|boiling point C=688
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|boiling point F=​1270
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|boiling point comment=
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|sublimation point K=
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|sublimation point C=
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|sublimation point F=
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|sublimation point ref=
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|sublimation point comment=
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|density gplstp=
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|density gplstp ref=
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|density gplstp comment=
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|density gpcm3nrt=1.532
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|density gpcm3nrt ref=
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|density gpcm3nrt comment=
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|density gpcm3nrt 2=
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|density gpcm3nrt 3=
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|density gpcm3mp=1.46
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|density gpcm3mp ref=
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|density gpcm3mp comment=
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|density gpcm3bp=
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|density gpcm3bp ref=
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|density gpcm3bp comment=
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|molar volume=
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|molar volume unit =
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|molar volume ref=
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|molar volume comment=
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|triple point K=312.41
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|triple point kPa=
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|triple point ref=
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|triple point comment=
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|triple point K 2=
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|triple point kPa 2=
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|triple point 2 ref=
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|triple point 2 comment=
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|critical point K=2093
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|critical point MPa=16
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|critical point ref=
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|critical point comment=(extrapolated)
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|heat fusion=2.19
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|heat fusion ref=
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|heat fusion comment=
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|heat fusion 2=
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|heat fusion 2 ref=
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|heat fusion 2 comment=
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|heat vaporization=69
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|heat vaporization ref=
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|heat vaporization comment=
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|heat capacity=31.06
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|heat capacity ref=
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|heat capacity comment=
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|heat capacity 2=
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|heat capacity 2 ref=
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|heat capacity 2 comment=
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|vapor pressure 1=434
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|vapor pressure 10=486
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|vapor pressure 100=552
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|vapor pressure 1 k=641
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|vapor pressure 10 k=769
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|vapor pressure 100 k=958
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|vapor pressure ref=
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|vapor pressure comment=
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|vapor pressure 1 2=
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|vapor pressure 10 2=
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|vapor pressure 100 2=
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|vapor pressure 1 k 2=
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|vapor pressure 10 k 2=
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|vapor pressure 2 ref=
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|vapor pressure 2 comment=
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<!-- Atomic properties -->
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|atomic properties comment=
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|oxidation states='''+1''', −1
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|oxidation states ref=
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|oxidation states comment=(a strongly basic oxide)
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|electronegativity=0.82
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|electronegativity ref=
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|electronegativity comment=
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|ionization energy 1=403
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|ionization energy 1 ref=
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|ionization energy 1 comment=
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|ionization energy 2=2632.1
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|ionization energy 2 ref=
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|ionization energy 2 comment=
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|ionization energy 3=3859.4
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|ionization energy 3 ref=
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|ionization energy 3 comment=
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|number of ionization energies=
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|ionization energy ref=
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|ionization energy comment=
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|atomic radius=248
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|atomic radius ref=
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|atomic radius comment=
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|atomic radius calculated=
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|atomic radius calculated ref=
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|atomic radius calculated comment=
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|covalent radius=220±9
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|covalent radius ref=
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|covalent radius comment=
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|Van der Waals radius=303
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|Van der Waals radius ref=
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|Van der Waals radius comment=
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<!-- Miscellanea -->
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|crystal structure=
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|crystal structure prefix=
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|crystal structure ref=
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|crystal structure comment=Body-centered cubic (bcc)
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|crystal structure 2=
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|crystal structure 2 prefix=
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|crystal structure 2 ref=
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|crystal structure 2 comment=
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|speed of sound=
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|speed of sound ref=
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|speed of sound comment=
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|speed of sound rod at 20=1300
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|speed of sound rod at 20 ref=
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|speed of sound rod at 20 comment=
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|speed of sound rod at r.t.=
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|speed of sound rod at r.t. ref=
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|speed of sound rod at r.t. comment=
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|thermal expansion=90
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|thermal expansion ref=
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|thermal expansion comment=
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|thermal expansion at 25=
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|thermal expansion at 25 ref=
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|thermal expansion at 25 comment=
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|thermal conductivity=58.2
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|thermal conductivity ref=
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|thermal conductivity comment=
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|thermal conductivity 2=
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|thermal diffusivity=
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|electrical resistivity=
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|electrical resistivity comment=
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|electrical resistivity at 0=
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|electrical resistivity at 0 ref=
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|electrical resistivity at 0 comment=
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|electrical resistivity at 20=128·10<sup>-9</sup>
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|electrical resistivity at 20 ref=
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|electrical resistivity at 20 comment=
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|band gap=
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|band gap ref=
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|band gap comment=
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|Curie point K=
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|Curie point ref=
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|Curie point comment=
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|magnetic ordering=Paramagnetic
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|magnetic ordering ref=
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|magnetic ordering comment=
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|tensile strength=
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|tensile strength ref=
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|tensile strength comment=
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|Young's modulus=2.4
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|Young's modulus ref=
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|Young's modulus comment=
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|Shear modulus=
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|Shear modulus ref=
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|Shear modulus comment=
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|Bulk modulus=2.5
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|Bulk modulus ref=
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|Bulk modulus comment=
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|Poisson ratio=0.3
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|Poisson ratio ref=
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|Poisson ratio comment=
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|Mohs hardness=
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|Mohs hardness comment=
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|Mohs hardness 2=
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|Vickers hardness=
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|Vickers hardness comment=
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|Brinell hardness=0.216
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|Brinell hardness ref=
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|Brinell hardness comment=
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|CAS number=7440-17-7
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|CAS number ref=
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|CAS number comment=
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<!-- History -->
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|naming=
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|predicted by=
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|prediction date ref=
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|prediction date=
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|discovered by=Robert Bunsen and Gustav Kirchhoff
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|discovery date ref=
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|discovery date=1861
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|first isolation by=George de Hevesy
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|first isolation date ref=
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|first isolation date=
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|discovery and first isolation by=
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|named by=
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|named date=
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|history comment label=
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|history comment=
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<!-- Isotopes -->
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|isotopes=
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|isotopes comment=
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|engvar=
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}}
 
'''Rubidium''' is an alkali metal with the chemical symbol '''Rb''' and an atomic number of 37. It is a relatively rare element due to its even distribution through the Earth's crust.  It does not have any known ores with a concentration higher than 1%. The world production of rubidium compounds is between 2-4 tonnes per year.
 
'''Rubidium''' is an alkali metal with the chemical symbol '''Rb''' and an atomic number of 37. It is a relatively rare element due to its even distribution through the Earth's crust.  It does not have any known ores with a concentration higher than 1%. The world production of rubidium compounds is between 2-4 tonnes per year.
  
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<references />
 
<references />
 
===Relevant Sciencemadness threads===
 
===Relevant Sciencemadness threads===
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=20496 Rubidium from the chloride]
  
 
[[Category:Elements]]
 
[[Category:Elements]]

Latest revision as of 21:40, 8 October 2017

Rubidium,  37Rb
General properties
Name, symbol Rubidium, Rb
Appearance Silvery-white
Rubidium in the periodic table
K
↑
Rb
↓
Cs
Krypton ← Rubidium → Strontium
Atomic number 37
Standard atomic weight (Ar) 85.4678(3)
Group, block (alkali metals); s-block
Period period 5
Electron configuration [Kr] 5s1
per shell
 2, 8, 18, 8, 1
Physical properties
Silvery-white
Phase Solid
Melting point 312.45 K ​(39.30 °C, ​​102.74 °F)
Boiling point 961 K ​(688 °C, ​​1270 °F)
Density near r.t. 1.532 g/cm3
when liquid, at  1.46 g/cm3
Triple point 312.41 K, ​ kPa
Critical point 2093 K, 16 MPa (extrapolated)
Heat of fusion 2.19 kJ/mol
Heat of 69 kJ/mol
Molar heat capacity 31.06 J/(mol·K)
 pressure
Atomic properties
Oxidation states +1, −1 ​(a strongly basic oxide)
Electronegativity Pauling scale: 0.82
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
Miscellanea
Crystal structure ​Body-centered cubic (bcc)
Speed of sound thin rod 1300 m/s (at 20 °C)
Thermal expansion 90 µm/(m·K)
Thermal conductivity 58.2 W/(m·K)
Electrical resistivity 128·10-9 Ω·m (at 20 °C)
Magnetic ordering Paramagnetic
Young's modulus 2.4 GPa
Bulk modulus 2.5 GPa
Poisson ratio 0.3
Brinell hardness 0.216 MPa
CAS Registry Number 7440-17-7
History
Discovery Robert Bunsen and Gustav Kirchhoff (1861)
First isolation George de Hevesy
· references

Rubidium is an alkali metal with the chemical symbol Rb and an atomic number of 37. It is a relatively rare element due to its even distribution through the Earth's crust. It does not have any known ores with a concentration higher than 1%. The world production of rubidium compounds is between 2-4 tonnes per year.

Properties

Chemical

Rubidium will react quickly and violently with water producing rubidium hydroxide and hydrogen. It also reacts violently with halogens in the presence of small amounts of water to form the corresponding halides.

Physical

Rubidium is a soft, silvery metal which will tarnish quickly in air. It has a relatively low melting point of 39°C. Like other alkali metals, it is quite soft and can easily be cut with a steel blade.

Availability

Rubidium metal is highly reactive and shipping regulations are very strict. It is offered by element dealers such as Metallium at very high prices(~$150/g). Rubidium salts are also available to the public on sites like eBay, priced at around $3/g.

Preparation

Rubidium metal can be prepared by the dry distillation of a rubidium halide and lithium metal, yielding rubidium vapor due to its low boiling point. This low boiling point is responsible for shifting the equilibrium of this reaction; the vapor can then be condensed in a glass vessel. This is quite dangerous and the risk of explosion is very high. It must be done in an inert atmosphere to prevent the spontaneous oxidation and ignition of the rubidium vapor at the high reaction temperatures.

Projects

Handling

Safety

Rubidium metal is extremely dangerous as it will catch fire in moist air and explode on contact with water. Upon long term storage in mineral oil, it will react with air to form shock sensitive explosive peroxides, similar to potassium. In its ionic form, rubidium ions are extremely similar to potassium ions, and replace them throughout the body. Due to their similarity, this caused no ill effects in study participants with 100x the normal amount (0.36g) of rubidium in a human. Mice were able to survive with significant fractions of potassium in their bodies replaced with rubidium, but when the rubidium:potassium ratio approached 1:1, the mice died.

Storage

Rubidium can be stored in mineral oil, but since rubidium is much more reactive than sodium or potassium, it will oxidize much faster. It's best stored under inert atmosphere, such as argon. For long term storage, it should be sealed in a glass ampoule.

Disposal

Since rubidium is expensive, it is best recycled if possible. However, rubidium ions are not toxic to the environment and moderate amounts may be discarded in municipal waste.

References

Relevant Sciencemadness threads

Retrieved from "https://www.sciencemadness.org/smwiki/index.php?title=Rubidium&oldid=7748"