cobalt

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

Description

Cobalt is a brittle, hard, transition metal with magnetic properties similar to those of iron. Cobalt is present in meteorites. Ore deposits are found in Zaire, Morocco and Canada. Cobalt-60 (⁶⁰Co) is an artificially produced isotope used as a source of g rays (high energy radiation). Cobalt salts colour glass a beautiful deep blue colour.

General information

Discoveror: Georg Brandt
Date discovered: 1735
Discovered at: Sweden
Meaning of name: From the German word "kobald" meaning "goblin" or evil spirit

Physical data

Standard state: solid at 298 K
Colour: lustrous, metallic, greyish tinge
Density of solid at ambient temperature/kg m^-3: 8900
Molar volume/cm³: 6.67

Radii /pm

Atomic: 152
Covalent (single bond):
Pauling radius for the ion [Co]^-: no data

Valence shell orbital radius maxima (R_max)

orbital	s	p	d	f
radius	131.9	no data	35.8	no data

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 1.88
Allred Rochow: 1.7

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: 1768
boiling point: 3200

Enthalpies /kJ mol^-1

fusion: 16.2
vaporization: 375

single bond enthalpies:

Co-F	Co-Cl	Co-Br	Co-I	Co-Co
no data	no data	no data	no data	167

Ionization enthalpies /kJ mol^-1

Number	Enthalpy
1st	758.0
2nd	1646
3rd	3232
4th	4950
5th	7670
6th	9840
7th	12400
8th	15100

Isotopes

This section gives some data for naturally occurring isotopes.

Nominal mass	Accurate mass	% natural abundance
59Co	58.9331976 (16)	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