|
|
Pronunciation | (sə-MAIR-ee-əm) |
---|
Appearance | silvery white |
---|
|
|
| 150.36(2)[1] |
---|
|
|
|
Atomic number (Z) | 62 |
---|
Group | f-block groups (no number) |
---|
Period | period 6 |
---|
Block | f-block |
---|
Electron configuration | [Xe] 4f6 6s2 |
---|
Electrons per shell | 2, 8, 18, 24, 8, 2 |
---|
|
Phase at STP | solid |
---|
Melting point | 1345 K (1072 °C, 1962 °F) |
---|
Boiling point | 2173 K (1900 °C, 3452 °F) |
---|
Density (near r.t.) | 7.52 g/cm3 |
---|
when liquid (at m.p.) | 7.16 g/cm3 |
---|
Heat of fusion | 8.62 kJ/mol |
---|
Heat of vaporization | 192 kJ/mol |
---|
Molar heat capacity | 29.54 J/(mol·K) |
---|
Vapor pressure
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
1001 |
1106 |
1240 |
(1421) |
(1675) |
(2061) |
|
|
Oxidation states | 0,[2] +1,[3] +2, +3 (a mildly basic oxide) |
---|
Electronegativity | Pauling scale: 1.17 |
---|
Ionization energies | - 1st: 544.5 kJ/mol
- 2nd: 1070 kJ/mol
- 3rd: 2260 kJ/mol
-
|
---|
Atomic radius | empirical: 180 pm |
---|
Covalent radius | 198±8 pm |
---|
Spectral lines of samarium |
|
Natural occurrence | primordial |
---|
Crystal structure | rhombohedral |
---|
Speed of sound thin rod | 2130 m/s (at 20 °C) |
---|
Thermal expansion | α, poly: 12.7 (at r.t.) µm/(m⋅K) |
---|
Thermal conductivity | 13.3 W/(m⋅K) |
---|
Electrical resistivity | α, poly: 0.940 (at r.t.) µΩ⋅m |
---|
Magnetic ordering | paramagnetic[4] |
---|
Molar magnetic susceptibility | +1860.0×10−6 cm3/mol (291 K)[5] |
---|
Young's modulus | α form: 49.7 GPa |
---|
Shear modulus | α form: 19.5 GPa |
---|
Bulk modulus | α form: 37.8 GPa |
---|
Poisson ratio | α form: 0.274 |
---|
Vickers hardness | 410–440 MPa |
---|
Brinell hardness | 440–600 MPa |
---|
CAS Number | 7440-19-9 |
---|
|
Naming | after the mineral samarskite (itself named after Vassili Samarsky-Bykhovets) |
---|
Discovery and first isolation | Lecoq de Boisbaudran (1879) |
---|
|
|
Main isotopes[6] |
Decay |
|
abundance |
half-life (t1/2) |
mode |
product |
144Sm |
3.08% |
stable |
145Sm |
synth |
340 d |
ε |
145Pm |
146Sm |
synth |
1.03×108 y |
α |
142Nd |
147Sm |
15% |
1.07×1011 y |
α |
143Nd |
148Sm |
11.3% |
6.3×1015 y |
α |
144Nd |
149Sm |
13.8% |
stable |
150Sm |
7.37% |
stable |
151Sm |
synth |
94.6 y |
β− |
151Eu |
152Sm |
26.7% |
stable |
153Sm |
synth |
46.28 h |
β− |
153Eu |
154Sm |
22.7% |
stable |
|
|
Category: Samarium | references |