Template:Good article is only for Wikipedia:Good articles.
Quick Facts Samarium, Pronunciation ...
Samarium, 62Sm |
|
Pronunciation | (sə-MAIR-ee-əm) |
---|
Appearance | silvery white |
---|
|
|
| |
---|
|
|
|
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 (at 20° C) | 7.518 g/cm3 [3] |
---|
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,[4] +1,[5] +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 (hR3) |
---|
Lattice constants | ar = 0.89834 nm α = 23.307° ah = 0.36291 nm ch = 2.6207 nm (at 20 °C)[3] |
---|
Thermal expansion | 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[6] |
---|
Molar magnetic susceptibility | +1860.0×10−6 cm3/mol (291 K)[7] |
---|
Young's modulus | 49.7 GPa |
---|
Shear modulus | 19.5 GPa |
---|
Bulk modulus | 37.8 GPa |
---|
Speed of sound thin rod | 2130 m/s (at 20 °C) |
---|
Poisson ratio | 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) |
---|
|
|
|
|
Category: Samarium | references |
Close
Samarium is a chemical element with symbol Sm and atomic number 62. It is a moderately hard silvery metal that readily oxidizes in air. Being a typical member of the lanthanide series, samarium usually assumes the oxidation state +3. Compounds of samarium(II) are also known, most notably the monoxide SmO, monochalcogenides SmS, SmSe and SmTe, as well as samarium(II) iodide. The last compound is a common reducing agent in chemical synthesis. Samarium has no significant biological role and is only slightly toxic.