Difference between revisions of "Europium"
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| − | '''Europium''' is a [[lanthanide]] with the symbol Eu and atomic number 63. It is a steel-gray metal about as reactive as calcium. Although difficult to find and rather expensive, it and its salts have very interesting properties that make it an excellent addition to the amateur chemist's lab. Among these properties are multi-colored [[fluorescence]], [[redox|redox chemistry]] and [[paramagnetism]], brought about by the element's half-filled f-shell. Europium can exist in a +2 state in a reducing environment, which can be an excellent exercise in preparing reduced compounds, as the reaction Eu<sup>2+</sup> → Eu<sup>3+</sup> + e<sup>-</sup> is even less favored than [[Chromium|Cr]]<sup>2+</sup> → Cr<sup>3+</sup> + e<sup>-</sup>, which is a standard exercise in the lab. | + | {{Infobox element |
| + | <!-- top --> | ||
| + | |image name= | ||
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| + | |image name 2= | ||
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| + | <!-- General properties --> | ||
| + | |name= Europium | ||
| + | |symbol= Eu | ||
| + | |pronounce= | ||
| + | |pronounce ref= | ||
| + | |pronounce comment= | ||
| + | |pronounce 2= | ||
| + | |alt name= | ||
| + | |alt names= | ||
| + | |allotropes= | ||
| + | |appearance= | ||
| + | <!-- Periodic table --> | ||
| + | |above= | ||
| + | |below= | ||
| + | |left= | ||
| + | |right= | ||
| + | |number= | ||
| + | |atomic mass= | ||
| + | |atomic mass 2= | ||
| + | |atomic mass ref= | ||
| + | |atomic mass comment= | ||
| + | |series= | ||
| + | |series ref= | ||
| + | |series comment= | ||
| + | |series color= | ||
| + | |group= | ||
| + | |group ref= | ||
| + | |group comment= | ||
| + | |period= | ||
| + | |period ref= | ||
| + | |period comment= | ||
| + | |block= | ||
| + | |block ref= | ||
| + | |block comment= | ||
| + | |electron configuration= | ||
| + | |electron configuration ref= | ||
| + | |electron configuration comment= | ||
| + | |electrons per shell= | ||
| + | |electrons per shell ref= | ||
| + | |electrons per shell comment= | ||
| + | <!-- Physical properties --> | ||
| + | |physical properties comment= | ||
| + | |color= | ||
| + | |phase= | ||
| + | |phase ref= | ||
| + | |phase comment= | ||
| + | |melting point K= | ||
| + | |melting point C= | ||
| + | |melting point F= | ||
| + | |melting point ref= | ||
| + | |melting point comment= | ||
| + | |boiling point K= | ||
| + | |boiling point C= | ||
| + | |boiling point F= | ||
| + | |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= | ||
| + | |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= | ||
| + | |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= | ||
| + | |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= | ||
| + | |critical point MPa= | ||
| + | |critical point ref= | ||
| + | |critical point comment= | ||
| + | |heat fusion= | ||
| + | |heat fusion ref= | ||
| + | |heat fusion comment= | ||
| + | |heat fusion 2= | ||
| + | |heat fusion 2 ref= | ||
| + | |heat fusion 2 comment= | ||
| + | |heat vaporization= | ||
| + | |heat vaporization ref= | ||
| + | |heat vaporization comment= | ||
| + | |heat capacity= | ||
| + | |heat capacity ref= | ||
| + | |heat capacity comment= | ||
| + | |heat capacity 2= | ||
| + | |heat capacity 2 ref= | ||
| + | |heat capacity 2 comment= | ||
| + | |vapor pressure 1= | ||
| + | |vapor pressure 10= | ||
| + | |vapor pressure 100= | ||
| + | |vapor pressure 1 k= | ||
| + | |vapor pressure 10 k= | ||
| + | |vapor pressure 100 k= | ||
| + | |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= | ||
| + | |oxidation states ref= | ||
| + | |oxidation states comment= | ||
| + | |electronegativity= | ||
| + | |electronegativity ref= | ||
| + | |electronegativity comment= | ||
| + | |ionization energy 1= | ||
| + | |ionization energy 1 ref= | ||
| + | |ionization energy 1 comment= | ||
| + | |ionization energy 2= | ||
| + | |ionization energy 2 ref= | ||
| + | |ionization energy 2 comment= | ||
| + | |ionization energy 3= | ||
| + | |ionization energy 3 ref= | ||
| + | |ionization energy 3 comment= | ||
| + | |number of ionization energies= | ||
| + | |ionization energy ref= | ||
| + | |ionization energy comment= | ||
| + | |atomic radius= | ||
| + | |atomic radius ref= | ||
| + | |atomic radius comment= | ||
| + | |atomic radius calculated= | ||
| + | |atomic radius calculated ref= | ||
| + | |atomic radius calculated comment= | ||
| + | |covalent radius= | ||
| + | |covalent radius ref= | ||
| + | |covalent radius comment= | ||
| + | |Van der Waals radius= | ||
| + | |Van der Waals radius ref= | ||
| + | |Van der Waals radius comment= | ||
| + | <!-- Miscellanea --> | ||
| + | |crystal structure= | ||
| + | |crystal structure prefix= | ||
| + | |crystal structure ref= | ||
| + | |crystal structure comment= | ||
| + | |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= | ||
| + | |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= | ||
| + | |thermal expansion ref= | ||
| + | |thermal expansion comment= | ||
| + | |thermal expansion at 25= | ||
| + | |thermal expansion at 25 ref= | ||
| + | |thermal expansion at 25 comment= | ||
| + | |thermal conductivity= | ||
| + | |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= | ||
| + | |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= | ||
| + | |magnetic ordering ref= | ||
| + | |magnetic ordering comment= | ||
| + | |tensile strength= | ||
| + | |tensile strength ref= | ||
| + | |tensile strength comment= | ||
| + | |Young's modulus= | ||
| + | |Young's modulus ref= | ||
| + | |Young's modulus comment= | ||
| + | |Shear modulus= | ||
| + | |Shear modulus ref= | ||
| + | |Shear modulus comment= | ||
| + | |Bulk modulus= | ||
| + | |Bulk modulus ref= | ||
| + | |Bulk modulus comment= | ||
| + | |Poisson ratio= | ||
| + | |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= | ||
| + | |Brinell hardness ref= | ||
| + | |Brinell hardness comment= | ||
| + | |CAS number= | ||
| + | |CAS number ref= | ||
| + | |CAS number comment= | ||
| + | <!-- History --> | ||
| + | |naming= | ||
| + | |predicted by= | ||
| + | |prediction date ref= | ||
| + | |prediction date= | ||
| + | |discovered by= | ||
| + | |discovery date ref= | ||
| + | |discovery date= | ||
| + | |first isolation by= | ||
| + | |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= | ||
| + | }} | ||
| + | '''Europium''' is a [[lanthanide]] with the symbol '''Eu''' and atomic number 63. It is a steel-gray metal about as reactive as calcium. Although difficult to find and rather expensive, it and its salts have very interesting properties that make it an excellent addition to the amateur chemist's lab. Among these properties are multi-colored [[fluorescence]], [[redox|redox chemistry]] and [[paramagnetism]], brought about by the element's half-filled f-shell. Europium can exist in a +2 state in a reducing environment, which can be an excellent exercise in preparing reduced compounds, as the reaction Eu<sup>2+</sup> → Eu<sup>3+</sup> + e<sup>-</sup> is even less favored than [[Chromium|Cr]]<sup>2+</sup> → Cr<sup>3+</sup> + e<sup>-</sup>, which is a standard exercise in the lab. | ||
==Properties== | ==Properties== | ||
Revision as of 22:01, 17 November 2016
| General properties | |||||
|---|---|---|---|---|---|
| Name, symbol | Europium, Eu | ||||
| Europium in the periodic table | |||||
| |||||
| Standard atomic weight (Ar) | |||||
| Group, block | , -block | ||||
| Period | period | ||||
| Electron configuration | |||||
| Physical properties | |||||
| Atomic properties | |||||
Europium is a lanthanide with the symbol Eu and atomic number 63. It is a steel-gray metal about as reactive as calcium. Although difficult to find and rather expensive, it and its salts have very interesting properties that make it an excellent addition to the amateur chemist's lab. Among these properties are multi-colored fluorescence, redox chemistry and paramagnetism, brought about by the element's half-filled f-shell. Europium can exist in a +2 state in a reducing environment, which can be an excellent exercise in preparing reduced compounds, as the reaction Eu2+ → Eu3+ + e- is even less favored than Cr2+ → Cr3+ + e-, which is a standard exercise in the lab.
Contents
Properties
Chemical
Europium is by far the most reactive lanthanide, quickly corroding in air. The highly favorable reaction Eu → Eu2+ + e- and the increased stability of europium(II) accelerates the corrosion rate of the metal such that a small piece exposed to dry air will corrode within a month. The resulting yellow powder, nearly the color of mustard, slowly fades as it turns from europium(II) to europium(III), the most stable form of europium. A mixed oxide of europium(II) and europium(III) has been reported, as have europium(II) sulfide, europium(II) chloride, and europium(II) sulfate, which is very similar to calcium and barium sulfate and highly insoluble.
Europium metal burns in air with a bright red flame, identical to that of samarium, and forms the oxide in air. When europium contacts water, it will react with water about as quickly as calcium metal, and will form the yellow divalent hydroxide, which slowly converts to the trivalent hydroxide.
Physical
Freshly cut europium is grayish, but quickly develops a thick layer of yellow and graphite-colored oxides. It is a relatively soft metal, and is relatively soft. Europium(II) compounds exhibit a blue fluorescence, and europium(III) compounds exhibit a red fluorescence. The fluorescence may be enhanced by the complexation of dipicolinate or other planar ligands to a europium atom.
Availability
Europium is more common than iodine on Earth, but it is hard to find and extremely expensive. Places like Sigma-Aldrich charge $1000 for five measly grams.[1] One source for europium, as well as other rare earth metals, is Metallium. It is sold in 5 gram (thankfully only $50) and 25 gram sizes, as well as rods, ampoules, and coins. Metallium also takes custom orders. Europium and its compounds may be occasionally found on eBay. Other places such as NewMet will sell europium rods, sheets, foils at any size and no minimum order, though the price is on request.
Projects
- Preparing reduced europium compounds
- Producing fluorescent crystals (blue and red)
- Producing triboluminescent europium tetrakis(dibenzoylmethide)triethylammonium
Safety
Safety
Europium metal, especially as a dust, should always be kept away from water and open flames. Europium fires can be identified by their bright red flames. Never use water to put out europium fire, as this will aggravate it. Class D fire extinguishers are recommended for this type of fire.
Storage
Europium requires storage under an inert atmosphere or mineral oil to prevent corrosion. When exposed to air, europium corrodes very easily, and it is not possible to reduce europium compounds to europium metal without an aprotic solvent.
Disposal
Best to try to recycle it.
