Samarium

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Samarium,  62Sm
Samarium-2.jpg
General properties
Appearance sillery white
Staundart atomic wecht (Ar, staundart) 150.36(2)
Samarium in the periodic cairt
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
-

Sm

Pu
promethiumsamariumeuropium
Atomic nummer (Z) 62
Group group n/a
Period period 6
Element category   lanthanide
Block f-block
Electron confeeguration [Xe] 6s2 4f6
Electrons per shell
2, 8, 18, 24, 8, 2
Pheesical properties
Phase (at STP) solit
Meltin pynt 1345 K ​(1072 °C, ​1962 °F)
Bylin pynt 2067 K ​(1794 °C, ​3261 °F)
Density (near r.t.) 7.52 g/cm3
when liquid (at m.p.) 7.16 g/cm3
Heat o fusion 8.62 kJ/mol
Heat o vapourisation 165 kJ/mol
Molar heat capacity 29.54 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1001 1106 1240 (1421) (1675) (2061)
Atomic properties
Oxidation states

4, 3, 2, 1

(mildly basic oxide)
Electronegativity Pauling scale: 1.17
Atomic radius empirical: 180 pm
Covalent radius 198±8 pm
Color lines in a spectral range
Miscellanea
Creestal structurrhombohedral
Rhombohedral creestal structur for samarium
Speed o soond thin rod 2130 m/s (at 20 °C)
Thermal expansion (r.t.) (α, poly) 12.7 µm/(m·K)
Thermal conductivity 13.3 W/(m·K)
Electrical resistivity (r.t.) (α, poly) 0.940 µ Ω·m
Magnetic orderin paramagnetic[1]
Young's modulus (α form) 49.7 GPa
Shear modulus (α form) 19.5 GPa
Bouk modulus (α form) 37.8 GPa
Poisson ratio (α form) 0.274
Vickers haurdness 412 MPa
Brinell haurdness 441 MPa
CAS Nummer 7440-19-9
History
Diskivery Lecoq de Boisbaudran (1879)
First isolation Lecoq de Boisbaudran (1879)
Main isotopes o samarium
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 (ββ) 154Gd
Decay modes in parentheses are predictit, but hae nae yet been observed
| references | in Wikidata

Samarium is a chemical element wi seembol Sm an atomic nummer 62. It is a moderately haird sillery metal that readily oxidizes in air. Bein a teepical member o the lanthanide series, samarium uisually assumes the oxidation state +3. Compoonds o samarium(II) are an aa kent, maist notably the monoxide SmO, monochalcogenides SmS, SmSe an SmTe, as well as samarium(II) iodide. The last compoond is a common reducin agent in chemical synthesis. Samarium haes na signeeficant biological role an is anly slichtly toxic.

References[eedit | eedit soorce]

  1. Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.