WebElements

Periodic Table

gadolinium

Atomic number: 64
Atomic weight: 157.25
Symbol: Gd
Group number: (lanthanide)
Electronic configuration: [Xe].4f7.5d1.6s2

Description

Gadolinium is silvery white, has a metallic lustre, and is is malleable and ductile. It is ferromagnetic (strongly attracted by a magnet).

The metal is relatively stable in dry air, but in moist air it tarnishes with the formation of a loosely adhering oxide film which "spalls" off and exposes more surface to oxidation. The metal reacts slowly with water and is soluble in dilute acid. Gadolinium has the highest thermal neutron capture cross-section of any known element.

General information

Discoveror: Jean de Marignac
Date discovered: 1880
Discovered at: Switzerland
Meaning of name: Named after J. "Gadolin", a Finnish chemist and minerologist

Physical data

Standard state: solid at 298 K
Colour: silvery white
Density of solid at ambient temperature/kg m-3: 7901
Molar volume/cm3: 19.90

Radii /pm

Atomic: 233
Covalent (single bond):
Pauling radius for the ion [Gd]-: no data

Valence shell orbital radius maxima (Rmax)
orbital s p d f
radius201.2no data102.129.7

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 1.20
Allred Rochow: 1.11

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.

ball-and-stick.gif

Temperatures (/K)

melting point: 1585
boiling point: 3523

Enthalpies /kJ mol-1

fusion: 10.0
vaporization: 306

single bond enthalpies:
Gd-F Gd-Cl Gd-Br Gd-I Gd-Gd
no data no data no data 343 no data

Ionization enthalpies /kJ mol-1

Number Enthalpy
1st593
2nd1167
3rd1990
4th4240
5th6250

Isotopes

This section gives some data for naturally occurring isotopes.
Nominal mass Accurate mass % natural abundance
152Gd151.919786 (4)0.20 (1)
154Gd153.920861 (4)2.18 (3)
155Gd154.922618 (4)14.80 (5)
156Gd155.922118 (4)20.47 (4)
157Gd156.923956 (4)15.65 (3)
158Gd157.924019 (4)24.84 (12)
160Gd159.927049 (4)21.86 (4)

Further Information

Copyright 1997 Mark Winter
Department of Chemistry at the University of Sheffield, Sheffield S3 7HF, England.

The current version of this document is at http://www.shef.ac.uk/~chem/web-elements-I/Gd.html