Difference between revisions of "Europium"
| Line 19: | Line 19: | ||
|alt names= | |alt names= | ||
|allotropes= | |allotropes= | ||
| − | |appearance= | + | |appearance=Silvery white |
<!-- Periodic table --> | <!-- Periodic table --> | ||
|above= | |above= | ||
| − | |below= | + | |below=[[Americium|Am]] |
| − | |left= | + | |left=[[Samarium]] |
| − | |right= | + | |right=[[Gadolinium]] |
| − | |number= | + | |number=63 |
| − | |atomic mass= | + | |atomic mass=151.964(1) |
|atomic mass 2= | |atomic mass 2= | ||
|atomic mass ref= | |atomic mass ref= | ||
| Line 37: | Line 37: | ||
|group ref= | |group ref= | ||
|group comment= | |group comment= | ||
| − | |period= | + | |period=6 |
|period ref= | |period ref= | ||
|period comment= | |period comment= | ||
| − | |block= | + | |block=f |
|block ref= | |block ref= | ||
|block comment= | |block comment= | ||
| − | |electron configuration= | + | |electron configuration=[Xe] 4f<sup>7</sup> 6s<sup>2</sup> |
|electron configuration ref= | |electron configuration ref= | ||
|electron configuration comment= | |electron configuration comment= | ||
| − | |electrons per shell= | + | |electrons per shell=2, 8, 18, 25, 8, 2 |
|electrons per shell ref= | |electrons per shell ref= | ||
|electrons per shell comment= | |electrons per shell comment= | ||
| Line 55: | Line 55: | ||
|phase ref= | |phase ref= | ||
|phase comment= | |phase comment= | ||
| − | |melting point K= | + | |melting point K=1099 |
| − | |melting point C= | + | |melting point C=826 |
| − | |melting point F= | + | |melting point F=1519 |
|melting point ref= | |melting point ref= | ||
|melting point comment= | |melting point comment= | ||
| − | |boiling point K= | + | |boiling point K=1802 |
| − | |boiling point C= | + | |boiling point C=1529 |
| − | |boiling point F= | + | |boiling point F=2784 |
|boiling point ref= | |boiling point ref= | ||
|boiling point comment= | |boiling point comment= | ||
| Line 73: | Line 73: | ||
|density gplstp ref= | |density gplstp ref= | ||
|density gplstp comment= | |density gplstp comment= | ||
| − | |density gpcm3nrt= | + | |density gpcm3nrt=5.264 |
|density gpcm3nrt ref= | |density gpcm3nrt ref= | ||
|density gpcm3nrt comment= | |density gpcm3nrt comment= | ||
| Line 82: | Line 82: | ||
|density gpcm3nrt 3 ref= | |density gpcm3nrt 3 ref= | ||
|density gpcm3nrt 3 comment= | |density gpcm3nrt 3 comment= | ||
| − | |density gpcm3mp= | + | |density gpcm3mp=5.13 |
|density gpcm3mp ref= | |density gpcm3mp ref= | ||
|density gpcm3mp comment= | |density gpcm3mp comment= | ||
| Line 104: | Line 104: | ||
|critical point ref= | |critical point ref= | ||
|critical point comment= | |critical point comment= | ||
| − | |heat fusion= | + | |heat fusion=9.21 |
|heat fusion ref= | |heat fusion ref= | ||
|heat fusion comment= | |heat fusion comment= | ||
| Line 110: | Line 110: | ||
|heat fusion 2 ref= | |heat fusion 2 ref= | ||
|heat fusion 2 comment= | |heat fusion 2 comment= | ||
| − | |heat vaporization= | + | |heat vaporization=176 |
|heat vaporization ref= | |heat vaporization ref= | ||
|heat vaporization comment= | |heat vaporization comment= | ||
| − | |heat capacity= | + | |heat capacity=27.66 |
|heat capacity ref= | |heat capacity ref= | ||
|heat capacity comment= | |heat capacity comment= | ||
| Line 119: | Line 119: | ||
|heat capacity 2 ref= | |heat capacity 2 ref= | ||
|heat capacity 2 comment= | |heat capacity 2 comment= | ||
| − | |vapor pressure 1= | + | |vapor pressure 1=863 |
| − | |vapor pressure 10= | + | |vapor pressure 10=957 |
| − | |vapor pressure 100= | + | |vapor pressure 100=1072 |
| − | |vapor pressure 1 k= | + | |vapor pressure 1 k=1234 |
| − | |vapor pressure 10 k= | + | |vapor pressure 10 k=1452 |
| − | |vapor pressure 100 k= | + | |vapor pressure 100 k=1796 |
|vapor pressure ref= | |vapor pressure ref= | ||
|vapor pressure comment= | |vapor pressure comment= | ||
| Line 137: | Line 137: | ||
<!-- Atomic properties --> | <!-- Atomic properties --> | ||
|atomic properties comment= | |atomic properties comment= | ||
| − | |oxidation states= | + | |oxidation states='''3''', '''2''', 1 |
|oxidation states ref= | |oxidation states ref= | ||
| − | |oxidation states comment= | + | |oxidation states comment=(a mildly basic oxide) |
| − | |electronegativity= | + | |electronegativity=1.2 |
|electronegativity ref= | |electronegativity ref= | ||
|electronegativity comment= | |electronegativity comment= | ||
| − | |ionization energy 1= | + | |ionization energy 1=547.1 |
|ionization energy 1 ref= | |ionization energy 1 ref= | ||
|ionization energy 1 comment= | |ionization energy 1 comment= | ||
| − | |ionization energy 2= | + | |ionization energy 2=1085 |
|ionization energy 2 ref= | |ionization energy 2 ref= | ||
|ionization energy 2 comment= | |ionization energy 2 comment= | ||
| − | |ionization energy 3= | + | |ionization energy 3=2404 |
|ionization energy 3 ref= | |ionization energy 3 ref= | ||
|ionization energy 3 comment= | |ionization energy 3 comment= | ||
| Line 155: | Line 155: | ||
|ionization energy ref= | |ionization energy ref= | ||
|ionization energy comment= | |ionization energy comment= | ||
| − | |atomic radius= | + | |atomic radius=180 |
|atomic radius ref= | |atomic radius ref= | ||
|atomic radius comment= | |atomic radius comment= | ||
| Line 161: | Line 161: | ||
|atomic radius calculated ref= | |atomic radius calculated ref= | ||
|atomic radius calculated comment= | |atomic radius calculated comment= | ||
| − | |covalent radius= | + | |covalent radius=198±6 |
|covalent radius ref= | |covalent radius ref= | ||
|covalent radius comment= | |covalent radius comment= | ||
| Line 171: | Line 171: | ||
|crystal structure prefix= | |crystal structure prefix= | ||
|crystal structure ref= | |crystal structure ref= | ||
| − | |crystal structure comment= | + | |crystal structure comment= Body-centered cubic (bcc) |
|crystal structure 2= | |crystal structure 2= | ||
|crystal structure 2 prefix= | |crystal structure 2 prefix= | ||
| Line 185: | Line 185: | ||
|speed of sound rod at r.t. ref= | |speed of sound rod at r.t. ref= | ||
|speed of sound rod at r.t. comment= | |speed of sound rod at r.t. comment= | ||
| − | |thermal expansion= | + | |thermal expansion=35.0 |
|thermal expansion ref= | |thermal expansion ref= | ||
| − | |thermal expansion comment= | + | |thermal expansion comment=(poly) |
|thermal expansion at 25= | |thermal expansion at 25= | ||
|thermal expansion at 25 ref= | |thermal expansion at 25 ref= | ||
|thermal expansion at 25 comment= | |thermal expansion at 25 comment= | ||
| − | |thermal conductivity= | + | |thermal conductivity=13.9 |
|thermal conductivity ref= | |thermal conductivity ref= | ||
|thermal conductivity comment= | |thermal conductivity comment= | ||
| Line 200: | Line 200: | ||
|thermal diffusivity ref= | |thermal diffusivity ref= | ||
|thermal diffusivity comment= | |thermal diffusivity comment= | ||
| − | |electrical resistivity= | + | |electrical resistivity=9·10<sup>-7</sup> |
|electrical resistivity unit prefix= | |electrical resistivity unit prefix= | ||
|electrical resistivity ref= | |electrical resistivity ref= | ||
| − | |electrical resistivity comment= | + | |electrical resistivity comment=(poly) |
|electrical resistivity at 0= | |electrical resistivity at 0= | ||
|electrical resistivity at 0 ref= | |electrical resistivity at 0 ref= | ||
| Line 216: | Line 216: | ||
|Curie point ref= | |Curie point ref= | ||
|Curie point comment= | |Curie point comment= | ||
| − | |magnetic ordering= | + | |magnetic ordering=Paramagnetic |
|magnetic ordering ref= | |magnetic ordering ref= | ||
|magnetic ordering comment= | |magnetic ordering comment= | ||
| Line 222: | Line 222: | ||
|tensile strength ref= | |tensile strength ref= | ||
|tensile strength comment= | |tensile strength comment= | ||
| − | |Young's modulus= | + | |Young's modulus=18.2 |
|Young's modulus ref= | |Young's modulus ref= | ||
|Young's modulus comment= | |Young's modulus comment= | ||
| − | |Shear modulus= | + | |Shear modulus=7.9 |
|Shear modulus ref= | |Shear modulus ref= | ||
|Shear modulus comment= | |Shear modulus comment= | ||
| − | |Bulk modulus= | + | |Bulk modulus=8.3 |
|Bulk modulus ref= | |Bulk modulus ref= | ||
|Bulk modulus comment= | |Bulk modulus comment= | ||
| − | |Poisson ratio= | + | |Poisson ratio=0.152 |
|Poisson ratio ref= | |Poisson ratio ref= | ||
|Poisson ratio comment= | |Poisson ratio comment= | ||
| Line 240: | Line 240: | ||
|Mohs hardness 2 ref= | |Mohs hardness 2 ref= | ||
|Mohs hardness 2 comment= | |Mohs hardness 2 comment= | ||
| − | |Vickers hardness= | + | |Vickers hardness=165–200 |
|Vickers hardness ref= | |Vickers hardness ref= | ||
|Vickers hardness comment= | |Vickers hardness comment= | ||
| Line 246: | Line 246: | ||
|Brinell hardness ref= | |Brinell hardness ref= | ||
|Brinell hardness comment= | |Brinell hardness comment= | ||
| − | |CAS number= | + | |CAS number=7440-53-1 |
|CAS number ref= | |CAS number ref= | ||
|CAS number comment= | |CAS number comment= | ||
<!-- History --> | <!-- History --> | ||
| − | |naming= | + | |naming=After Europe |
|predicted by= | |predicted by= | ||
|prediction date ref= | |prediction date ref= | ||
| Line 260: | Line 260: | ||
|first isolation date ref= | |first isolation date ref= | ||
|first isolation date= | |first isolation date= | ||
| − | |discovery and first isolation by= | + | |discovery and first isolation by=Eugène-Anatole Demarçay (1896, 1901) |
|named by= | |named by= | ||
|named date ref= | |named date ref= | ||
Revision as of 19:17, 15 October 2017
| General properties | |||||
|---|---|---|---|---|---|
| Name, symbol | Europium, Eu | ||||
| Appearance | Silvery white | ||||
| Europium in the periodic table | |||||
| |||||
| Atomic number | 63 | ||||
| Standard atomic weight (Ar) | 151.964(1) | ||||
| Group, block | , f-block | ||||
| Period | period 6 | ||||
| Electron configuration | [Xe] 4f7 6s2 | ||||
per shell | 2, 8, 18, 25, 8, 2 | ||||
| Physical properties | |||||
| Melting point | 1099 K (826 °C, 1519 °F) | ||||
| Boiling point | 1802 K (1529 °C, 2784 °F) | ||||
| Density near r.t. | 5.264 g/cm3 | ||||
| when liquid, at | 5.13 g/cm3 | ||||
| Heat of fusion | 9.21 kJ/mol | ||||
| Heat of | 176 kJ/mol | ||||
| Molar heat capacity | 27.66 J/(mol·K) | ||||
| pressure | |||||
| Atomic properties | |||||
| Oxidation states | 3, 2, 1 (a mildly basic oxide) | ||||
| Electronegativity | Pauling scale: 1.2 | ||||
| energies |
1st: 547.1 kJ/mol 2nd: 1085 kJ/mol 3rd: 2404 kJ/mol | ||||
| Atomic radius | empirical: 180 pm | ||||
| Covalent radius | 198±6 pm | ||||
| Miscellanea | |||||
| Crystal structure | Body-centered cubic (bcc) | ||||
| Thermal expansion | 35.0 µm/(m·K) (poly) | ||||
| Thermal conductivity | 13.9 W/(m·K) | ||||
| Electrical resistivity | 9·10-7 Ω·m (poly) | ||||
| Magnetic ordering | Paramagnetic | ||||
| Young's modulus | 18.2 GPa | ||||
| Shear modulus | 7.9 GPa | ||||
| Bulk modulus | 8.3 GPa | ||||
| Poisson ratio | 0.152 | ||||
| Vickers hardness | 165–200 MPa | ||||
| CAS Registry Number | 7440-53-1 | ||||
| History | |||||
| Naming | After Europe | ||||
| Discovery and first isolation | Eugène-Anatole Demarçay (1896, 1901) | ||||
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.
