samarium

• Description
• General information
• Physical data
• Radii
• Electronegativities
• Solid state structure
• Temperatures
• Enthalpies
• Ionization Enthalpies
• Isotopes
• Further information

Description

Samarium has a bright silver lustre and is reasonably stable in air. It ignites in air at 150°C. It is a rare earth metal. It is found with other rare earth elements in minerals including monazite and bastanite and is used in electronics industries.

General information

Discoveror: Paul Emile Lecoq de Boisbaudran
Date discovered: 1879
Discovered at: France
Meaning of name: Named after "Samarskite" (a mineral)

Physical data

Standard state: solid at 298 K
Colour: silvery white
Density of solid at ambient temperature/kg m^-3: 7353
Molar volume/cm³: 19.98

Radii /pm

Atomic: 238
Covalent (single bond):
Pauling radius for the ion [Sm]^-: no data

Valence shell orbital radius maxima (R_max)

orbital	s	p	d	f
radius	216.4	no data	no data	32.1

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 1.17
Allred Rochow: 1.07

Crystal Structure

structure: trigonal

The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.

Temperatures (/K)

melting point: 1345
boiling point: 2076

Enthalpies /kJ mol^-1

fusion: 8.9
vaporization: 178

single bond enthalpies:

Sm-F	Sm-Cl	Sm-Br	Sm-I	Sm-Sm
no data	no data	no data	285	no data

Ionization enthalpies /kJ mol^-1

Number	Enthalpy
1st	543
2nd	1068
3rd	2260
4th	3990
5th	6050

Isotopes

This section gives some data for naturally occurring isotopes.

Nominal mass	Accurate mass	% natural abundance
144Sm	143.911998 (4)	3.1 (1)
147Sm	146.914894 (4)	15.0 (2)
148Sm	147.914819 (4)	11.3 (1)
149Sm	148.917180 (4)	13.8 (1)
150Sm	149.917273 (4)	7.4 (1)
152Sm	151.919728 (4)	26.7 (2)
154Sm	153.922205 (4)	22.7 (2)

Further Information

• Additional information about WebElements 1.2.2
• This is a licensed copy (here is the full list) of WebElements 1.2.2 and contains a subset of the material contained within the main version of WebElements (version 2)
• For further information please try WebElements version 2
• Sheffield Chemdex: perhaps the largest internet chemistry directory
• Sheffield Chemputer: interactive chemistry calculators on the WWW