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Europium |
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Pronunciation | (yoor-OH-pee-əm) |
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Appearance | sillrry white, wi a pale yellsr tint;[1] but rarely seen without oxide discoloration |
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Standard atomic weight Ar, std(Eu) | 7002151964000000000♠151.964(1)[2] |
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Europium in the periodic cairt |
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– ↑ Eu ↓ Am |
samarium ← europium → gadolinium |
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Atomic nummer (Z) | 63 |
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Group | group n/a |
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Period | period 6 |
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Block | f-block |
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Element category | Lanthanide |
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Electron confeeguration | [Xe] 4f7 6s2 |
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Electrons per shell | 2, 8, 18, 25, 8, 2 |
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Pheesical properties |
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Phase at STP | solid |
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Meltin pynt | 1099 K (826 °C, 1519 °F) |
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Bylin pynt | 1802 K (1529 °C, 2784 °F) |
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Density (near r.t.) | 5.264 g/cm3 |
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when liquid (at m.p.) | 5.13 g/cm3 |
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Heat o fusion | 9.21 kJ/mol |
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Heat o vapourisation | 176 kJ/mol |
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Molar heat capacity | 27.66 J/(mol·K) |
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Vapour pressur
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
863 |
957 |
1072 |
1234 |
1452 |
1796 |
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Atomic properties |
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Oxidation states | +1, +2, +3 (a mildly basic oxide) |
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Electronegativity | Pauling scale: 1.2 |
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Ionisation energies | - 1st: 547.1 kJ/mol
- 2nd: 1085 kJ/mol
- 3rd: 2404 kJ/mol
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Atomic radius | empirical: 180 pm |
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Covalent radius | 198±6 pm |
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Spectral lines o europium |
Ither properties |
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Naitural occurrence | primordial |
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Creestal structur | bouk-centred cubic |
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Thermal expansion | poly: 35.0 µm/(m·K) (at r.t.) |
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Thermal conductivity | est. 13.9 W/(m·K) |
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Electrical resistivity | poly: 0.900 µΩ·m (at r.t.) |
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Magnetic orderin | paramagnetic[3] |
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Magnetic susceptibility | +34,000.0·10−6 cm3/mol[4] |
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Young's modulus | 18.2 GPa |
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Shear modulus | 7.9 GPa |
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Bulk modulus | 8.3 GPa |
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Poisson ratio | 0.152 |
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Vickers haurdness | 165–200 MPa |
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CAS Nummer | 7440-53-1 |
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History |
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Namin | efter Europe |
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Diskivery an first isolation | Eugène-Anatole Demarçay (1896, 1901) |
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Main isotopes o europium |
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Isotope |
Abundance |
Hauf-life (t1/2) |
Decay mode |
Product |
150Eu |
syn |
36.9 y |
ε |
150Sm |
151Eu |
47.8% |
5×1018 y |
α |
147Pm |
152Eu |
syn |
13.54 y |
ε |
152Sm |
β− |
152Gd |
153Eu |
52.2% |
stable |
154Eu |
syn |
8.59 y |
β− |
154Gd |
155Eu |
syn |
4.76 y |
β− |
155Gd |
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| references |