Samarium

Samarium, ₆₂Sm
Samarium
Pronunciation	/səˈmɛəriəm/ (sə-MAIR-ee-əm)
Appearance	sillery white
Standard atomic weight Ar, std(Sm)	150.36(2)
Samarium in the periodic cairt
	promethium ← samarium → europium
Atomic nummer (Z)	62
Group	group n/a
Period	period 6
Block	f-block
Element category	Lanthanide
Electron confeeguration	[Xe] 4f6 6s2
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)
Atomic properties
Oxidation states	0, +1, +2, +3 (a mildly basic oxide)
Electronegativity	Pauling scale: 1.17
Atomic radius	empirical: 180 pm
Covalent radius	198±8 pm
	Colour lines in a spectral rangeSpectral lines o samarium
Ither properties
Naitural occurrence	primordial
Creestal structur	rhombohedral
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
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 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
(α)	140Nd
	Decay modes in parentheses are predictit, but hae nae yet been observed
	view; talk; edit; \| references

Samarium is a chemical element wi symbol 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

↑ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
↑ Yttrium and all lanthanides except Ce, Pm, Eu, Tm, Yb have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017.
↑ Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.

[CIAAW2013-1] Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.

[Cloke1993-2] Yttrium and all lanthanides except Ce, Pm, Eu, Tm, Yb have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017.

[magnet-3] Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.

[1]

[2]

[3]