terbium

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

Description

Terbium is reasonably stable in air. It is a silvery-grey metal, and is malleable, ductile, and soft enough to be cut with a knife. It is a rare earth metal found in cerite, gadolinite and monazite. The element itself was isolated only recently.

General information

Discoveror: Carl Mosander
Date discovered: 1843
Discovered at: Sweden
Meaning of name: Named after "Ytterby", a town in Sweden

Physical data

Standard state: solid at 298 K
Colour: silvery white
Density of solid at ambient temperature/kg m^-3: 8219
Molar volume/cm³: 19.30

Radii /pm

Atomic: 225
Covalent (single bond):
Pauling radius for the ion [Tb]^-: no data

Valence shell orbital radius maxima (R_max)

orbital	s	p	d	f
radius	209.3	no data	no data	29.1

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: no data
Allred Rochow: 1.10

Crystal Structure

structure: hcp (hexagonal close-packed)

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: 1629
boiling point: 3503

Enthalpies /kJ mol^-1

fusion: 10.5
vaporization: 293

single bond enthalpies:

Tb-F	Tb-Cl	Tb-Br	Tb-I	Tb-Tb
no data	no data	no data	339	131.4

Ionization enthalpies /kJ mol^-1

Number	Enthalpy
1st	565
2nd	1112
3rd	2110
4th	3840
5th	6410

Isotopes

This section gives some data for naturally occurring isotopes.

Nominal mass	Accurate mass	% natural abundance
159Tb	158.925342 (4)	100

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