Difference between revisions of "Rubidium"
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− | '''Rubidium''' is an alkali metal with the chemical symbol Rb and an atomic number of 37. It is a rare element due to its even distribution through the Earth's crust | + | {{Infobox element |
+ | <!-- top --> | ||
+ | |image name= | ||
+ | |image alt= | ||
+ | |image size= | ||
+ | |image name comment= | ||
+ | |image name 2= | ||
+ | |image alt 2= | ||
+ | |image size 2= | ||
+ | |image name 2 comment= | ||
+ | <!-- General properties --> | ||
+ | |name=Rubidium | ||
+ | |symbol=Rb | ||
+ | |pronounce= | ||
+ | |pronounce ref= | ||
+ | |pronounce comment= | ||
+ | |pronounce 2= | ||
+ | |alt name= | ||
+ | |alt names= | ||
+ | |allotropes= | ||
+ | |appearance=Silvery-white | ||
+ | <!-- Periodic table --> | ||
+ | |above=[[Potassium|K]] | ||
+ | |below=[[Caesium|Cs]] | ||
+ | |left=[[Krypton]] | ||
+ | |right=[[Strontium]] | ||
+ | |number=37 | ||
+ | |atomic mass=85.4678(3) | ||
+ | |atomic mass 2= | ||
+ | |atomic mass ref= | ||
+ | |atomic mass comment= | ||
+ | |series= | ||
+ | |series ref= | ||
+ | |series comment= | ||
+ | |series color= | ||
+ | |group=1 | ||
+ | |group ref= | ||
+ | |group comment=(alkali metals) | ||
+ | |period=5 | ||
+ | |period ref= | ||
+ | |period comment= | ||
+ | |block=s | ||
+ | |block ref= | ||
+ | |block comment= | ||
+ | |electron configuration=[Kr] 5s<sup>1</sup> | ||
+ | |electron configuration ref= | ||
+ | |electron configuration comment= | ||
+ | |electrons per shell=2, 8, 18, 8, 1 | ||
+ | |electrons per shell ref= | ||
+ | |electrons per shell comment= | ||
+ | <!-- Physical properties --> | ||
+ | |physical properties comment= | ||
+ | |color=Silvery-white | ||
+ | |phase=Solid | ||
+ | |phase ref= | ||
+ | |phase comment= | ||
+ | |melting point K=312.45 | ||
+ | |melting point C=39.30 | ||
+ | |melting point F=102.74 | ||
+ | |melting point ref= | ||
+ | |melting point comment= | ||
+ | |boiling point K=961 | ||
+ | |boiling point C=688 | ||
+ | |boiling point F=1270 | ||
+ | |boiling point ref= | ||
+ | |boiling point comment= | ||
+ | |sublimation point K= | ||
+ | |sublimation point C= | ||
+ | |sublimation point F= | ||
+ | |sublimation point ref= | ||
+ | |sublimation point comment= | ||
+ | |density gplstp= | ||
+ | |density gplstp ref= | ||
+ | |density gplstp comment= | ||
+ | |density gpcm3nrt=1.532 | ||
+ | |density gpcm3nrt ref= | ||
+ | |density gpcm3nrt comment= | ||
+ | |density gpcm3nrt 2= | ||
+ | |density gpcm3nrt 2 ref= | ||
+ | |density gpcm3nrt 2 comment= | ||
+ | |density gpcm3nrt 3= | ||
+ | |density gpcm3nrt 3 ref= | ||
+ | |density gpcm3nrt 3 comment= | ||
+ | |density gpcm3mp=1.46 | ||
+ | |density gpcm3mp ref= | ||
+ | |density gpcm3mp comment= | ||
+ | |density gpcm3bp= | ||
+ | |density gpcm3bp ref= | ||
+ | |density gpcm3bp comment= | ||
+ | |molar volume= | ||
+ | |molar volume unit = | ||
+ | |molar volume ref= | ||
+ | |molar volume comment= | ||
+ | |triple point K=312.41 | ||
+ | |triple point kPa= | ||
+ | |triple point ref= | ||
+ | |triple point comment= | ||
+ | |triple point K 2= | ||
+ | |triple point kPa 2= | ||
+ | |triple point 2 ref= | ||
+ | |triple point 2 comment= | ||
+ | |critical point K=2093 | ||
+ | |critical point MPa=16 | ||
+ | |critical point ref= | ||
+ | |critical point comment=(extrapolated) | ||
+ | |heat fusion=2.19 | ||
+ | |heat fusion ref= | ||
+ | |heat fusion comment= | ||
+ | |heat fusion 2= | ||
+ | |heat fusion 2 ref= | ||
+ | |heat fusion 2 comment= | ||
+ | |heat vaporization=69 | ||
+ | |heat vaporization ref= | ||
+ | |heat vaporization comment= | ||
+ | |heat capacity=31.06 | ||
+ | |heat capacity ref= | ||
+ | |heat capacity comment= | ||
+ | |heat capacity 2= | ||
+ | |heat capacity 2 ref= | ||
+ | |heat capacity 2 comment= | ||
+ | |vapor pressure 1=434 | ||
+ | |vapor pressure 10=486 | ||
+ | |vapor pressure 100=552 | ||
+ | |vapor pressure 1 k=641 | ||
+ | |vapor pressure 10 k=769 | ||
+ | |vapor pressure 100 k=958 | ||
+ | |vapor pressure ref= | ||
+ | |vapor pressure comment= | ||
+ | |vapor pressure 1 2= | ||
+ | |vapor pressure 10 2= | ||
+ | |vapor pressure 100 2= | ||
+ | |vapor pressure 1 k 2= | ||
+ | |vapor pressure 10 k 2= | ||
+ | |vapor pressure 100 k 2= | ||
+ | |vapor pressure 2 ref= | ||
+ | |vapor pressure 2 comment= | ||
+ | <!-- Atomic properties --> | ||
+ | |atomic properties comment= | ||
+ | |oxidation states='''+1''', −1 | ||
+ | |oxidation states ref= | ||
+ | |oxidation states comment=(a strongly basic oxide) | ||
+ | |electronegativity=0.82 | ||
+ | |electronegativity ref= | ||
+ | |electronegativity comment= | ||
+ | |ionization energy 1=403 | ||
+ | |ionization energy 1 ref= | ||
+ | |ionization energy 1 comment= | ||
+ | |ionization energy 2=2632.1 | ||
+ | |ionization energy 2 ref= | ||
+ | |ionization energy 2 comment= | ||
+ | |ionization energy 3=3859.4 | ||
+ | |ionization energy 3 ref= | ||
+ | |ionization energy 3 comment= | ||
+ | |number of ionization energies= | ||
+ | |ionization energy ref= | ||
+ | |ionization energy comment= | ||
+ | |atomic radius=248 | ||
+ | |atomic radius ref= | ||
+ | |atomic radius comment= | ||
+ | |atomic radius calculated= | ||
+ | |atomic radius calculated ref= | ||
+ | |atomic radius calculated comment= | ||
+ | |covalent radius=220±9 | ||
+ | |covalent radius ref= | ||
+ | |covalent radius comment= | ||
+ | |Van der Waals radius=303 | ||
+ | |Van der Waals radius ref= | ||
+ | |Van der Waals radius comment= | ||
+ | <!-- Miscellanea --> | ||
+ | |crystal structure= | ||
+ | |crystal structure prefix= | ||
+ | |crystal structure ref= | ||
+ | |crystal structure comment=Body-centered cubic (bcc) | ||
+ | |crystal structure 2= | ||
+ | |crystal structure 2 prefix= | ||
+ | |crystal structure 2 ref= | ||
+ | |crystal structure 2 comment= | ||
+ | |speed of sound= | ||
+ | |speed of sound ref= | ||
+ | |speed of sound comment= | ||
+ | |speed of sound rod at 20=1300 | ||
+ | |speed of sound rod at 20 ref= | ||
+ | |speed of sound rod at 20 comment= | ||
+ | |speed of sound rod at r.t.= | ||
+ | |speed of sound rod at r.t. ref= | ||
+ | |speed of sound rod at r.t. comment= | ||
+ | |thermal expansion=90 | ||
+ | |thermal expansion ref= | ||
+ | |thermal expansion comment= | ||
+ | |thermal expansion at 25= | ||
+ | |thermal expansion at 25 ref= | ||
+ | |thermal expansion at 25 comment= | ||
+ | |thermal conductivity=58.2 | ||
+ | |thermal conductivity ref= | ||
+ | |thermal conductivity comment= | ||
+ | |thermal conductivity 2= | ||
+ | |thermal conductivity 2 ref= | ||
+ | |thermal conductivity 2 comment= | ||
+ | |thermal diffusivity= | ||
+ | |thermal diffusivity ref= | ||
+ | |thermal diffusivity comment= | ||
+ | |electrical resistivity= | ||
+ | |electrical resistivity unit prefix= | ||
+ | |electrical resistivity ref= | ||
+ | |electrical resistivity comment= | ||
+ | |electrical resistivity at 0= | ||
+ | |electrical resistivity at 0 ref= | ||
+ | |electrical resistivity at 0 comment= | ||
+ | |electrical resistivity at 20=128·10<sup>-9</sup> | ||
+ | |electrical resistivity at 20 ref= | ||
+ | |electrical resistivity at 20 comment= | ||
+ | |band gap= | ||
+ | |band gap ref= | ||
+ | |band gap comment= | ||
+ | |Curie point K= | ||
+ | |Curie point ref= | ||
+ | |Curie point comment= | ||
+ | |magnetic ordering=Paramagnetic | ||
+ | |magnetic ordering ref= | ||
+ | |magnetic ordering comment= | ||
+ | |tensile strength= | ||
+ | |tensile strength ref= | ||
+ | |tensile strength comment= | ||
+ | |Young's modulus=2.4 | ||
+ | |Young's modulus ref= | ||
+ | |Young's modulus comment= | ||
+ | |Shear modulus= | ||
+ | |Shear modulus ref= | ||
+ | |Shear modulus comment= | ||
+ | |Bulk modulus=2.5 | ||
+ | |Bulk modulus ref= | ||
+ | |Bulk modulus comment= | ||
+ | |Poisson ratio=0.3 | ||
+ | |Poisson ratio ref= | ||
+ | |Poisson ratio comment= | ||
+ | |Mohs hardness= | ||
+ | |Mohs hardness ref= | ||
+ | |Mohs hardness comment= | ||
+ | |Mohs hardness 2= | ||
+ | |Mohs hardness 2 ref= | ||
+ | |Mohs hardness 2 comment= | ||
+ | |Vickers hardness= | ||
+ | |Vickers hardness ref= | ||
+ | |Vickers hardness comment= | ||
+ | |Brinell hardness=0.216 | ||
+ | |Brinell hardness ref= | ||
+ | |Brinell hardness comment= | ||
+ | |CAS number=7440-17-7 | ||
+ | |CAS number ref= | ||
+ | |CAS number comment= | ||
+ | <!-- History --> | ||
+ | |naming= | ||
+ | |predicted by= | ||
+ | |prediction date ref= | ||
+ | |prediction date= | ||
+ | |discovered by=Robert Bunsen and Gustav Kirchhoff | ||
+ | |discovery date ref= | ||
+ | |discovery date=1861 | ||
+ | |first isolation by=George de Hevesy | ||
+ | |first isolation date ref= | ||
+ | |first isolation date= | ||
+ | |discovery and first isolation by= | ||
+ | |named by= | ||
+ | |named date ref= | ||
+ | |named date= | ||
+ | |history comment label= | ||
+ | |history comment= | ||
+ | <!-- Isotopes --> | ||
+ | |isotopes= | ||
+ | |isotopes comment= | ||
+ | |engvar= | ||
+ | }} | ||
+ | '''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== | ==Properties== | ||
===Chemical=== | ===Chemical=== | ||
− | Rubidium will react quickly and violently with water producing rubidium hydroxide and hydrogen. It | + | 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=== | ===Physical=== | ||
− | Rubidium is a soft, silvery metal which will tarnish quickly in air. It can | + | 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== | ==Availability== | ||
− | Rubidium metal is | + | Rubidium metal is highly reactive and shipping regulations are very strict. It is offered by element dealers such as [http://www.elementsales.com 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== | ==Preparation== | ||
− | Rubidium metal can be prepared by dry distillation of a rubidium halide and lithium metal, yielding | + | 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== | ==Projects== | ||
Line 19: | Line 293: | ||
==Handling== | ==Handling== | ||
===Safety=== | ===Safety=== | ||
− | Rubidium metal is extremely dangerous as it will catch fire in moist air and explode on contact with water. | + | 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=== | ===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. | + | 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=== | ===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== | ==References== | ||
<references /> | <references /> | ||
===Relevant Sciencemadness threads=== | ===Relevant Sciencemadness threads=== | ||
+ | *[http://www.sciencemadness.org/talk/viewthread.php?tid=20496 Rubidium from the chloride] | ||
+ | |||
+ | [[Category:Elements]] | ||
+ | [[Category:Metals]] | ||
+ | [[Category:Alkali metals]] | ||
+ | [[Category:Materials that react with water]] | ||
+ | [[Category:Materials unstable in acidic solution]] | ||
+ | [[Category:Air-sensitive materials]] | ||
+ | [[Category:Pyrophoric materials]] | ||
+ | [[Category:S-block]] |
Latest revision as of 21:40, 8 October 2017
General properties | |||||
---|---|---|---|---|---|
Name, symbol | Rubidium, Rb | ||||
Appearance | Silvery-white | ||||
Rubidium in the periodic table | |||||
| |||||
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 | ||||
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.
Contents
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
- Make rubidium hydroxide
- Rubidium suboxides
- Colored flash powders with rubidium salts
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.