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Samarium |
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Pronunciation | (sə-MAIR-ee-əm) |
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Appearance | sillery white |
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Standard atomic weight Ar, std(Sm) | 7002150360000000000♠150.36(2)[1] |
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Samarium in the periodic cairt |
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- ↑ Sm ↓ Pu |
promethium ← samarium → europium |
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Atomic nummer (Z) | 62 |
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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] 4f6 6s2 |
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Electrons per shell | 2, 8, 18, 24, 8, 2 |
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Pheesical properties |
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Phase at STP | solit |
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Meltin pynt | 1345 K (1072 °C, 1962 °F) |
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Bylin pynt | 2067 K (1794 °C, 3261 °F) |
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Density (near r.t.) | 7.52 g/cm3 |
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when liquid (at m.p.) | 7.16 g/cm3 |
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Heat o fusion | 8.62 kJ/mol |
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Heat o vapourisation | 165 kJ/mol |
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Molar heat capacity | 29.54 J/(mol·K) |
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Vapour pressur
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
1001 |
1106 |
1240 |
(1421) |
(1675) |
(2061) |
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Atomic properties |
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Oxidation states | 0,[2] +1, +2, +3 (a mildly basic oxide) |
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Electronegativity | Pauling scale: 1.17 |
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Atomic radius | empirical: 180 pm |
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Covalent radius | 198±8 pm |
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Spectral lines o samarium |
Ither properties |
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Naitural occurrence | primordial |
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Creestal structur | rhombohedral |
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Speed o soond thin rod | 2130 m/s (at 20 °C) |
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Thermal expansion | (r.t.) (α, poly) 12.7 µm/(m·K) |
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Thermal conductivity | 13.3 W/(m·K) |
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Electrical resistivity | (r.t.) (α, poly) 0.940 µ Ω·m |
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Magnetic orderin | paramagnetic[3] |
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Young's modulus | (α form) 49.7 GPa |
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Shear modulus | (α form) 19.5 GPa |
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Bulk modulus | (α form) 37.8 GPa |
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Poisson ratio | (α form) 0.274 |
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Vickers haurdness | 412 MPa |
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Brinell haurdness | 441 MPa |
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CAS Nummer | 7440-19-9 |
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History |
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Diskivery | Lecoq de Boisbaudran (1879) |
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First isolation | Lecoq de Boisbaudran (1879) |
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Main isotopes o samarium |
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Isotope |
Abundance |
Hauf-life (t1/2) |
Decay mode |
Product |
144Sm |
3.07% |
- |
(β+β+) |
144Nd |
(α) |
140Nd |
145Sm |
syn |
340 d |
ε |
145Pm |
146Sm |
trace |
1.03×108 y |
α |
142Nd |
147Sm |
14.99% |
1.06×1011 y |
α |
143Nd |
148Sm |
11.24% |
7×1015 y |
α |
144Nd |
149Sm |
13.82% |
>2×1015 y |
(α) |
145Nd |
150Sm |
7.38% |
- |
(α) |
146Nd |
151Sm |
syn |
90 y |
β− |
151Eu |
152Sm |
26.75% |
- |
(α) |
148Nd |
153Sm |
syn |
46.284 h |
β− |
153Eu |
154Sm |
22.75% |
>2.3×1018 y |
(β−β−) |
154Gd |
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Decay modes in parentheses are predictit, but hae nae yet been observed |
| references |