Periodic Table


Atomic number: 51
Atomic weight: 121.760
Symbol: Sb
Group number: 15
Electronic configuration: [Kr].4d10.5s2.5p3


Metallic antimony is an extremely brittle metal of a flaky, crystalline texture. It is bluish white and has a metallic lustre. It is not acted on by air at room temperature, but burns brilliantly when heated with the formation of white fumes. It is a poor conductor of heat and electricity.

Antimony and its compounds are toxic. It is found mostly with other minerals and in stibnite.

General information

Discoveror: Known since ancient times
Date discovered:
Discovered at: not known
Meaning of name: From the Greek words "anti + monos" meaning "not alone" (the origin of the symbol Sb comes from the Latin word "stibium")

Physical data

Standard state: solid at 298 K
Colour: silvery lustrous grey
Density of solid at ambient temperature/kg m-3: 6697
Molar volume/cm3: 18.19

Radii /pm

Atomic: 133
Covalent (single bond):
Pauling radius for the ion [Sb]-: 295

Valence shell orbital radius maxima (Rmax)
orbital s p d f
radius106.5126.644.7no data


Both values are quoted on the Pauling scale.

Pauling: 2.05
Allred Rochow: 1.82

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: 903.78
boiling point: 1860

Enthalpies /kJ mol-1

fusion: 19.7
vaporization: 68

single bond enthalpies:
Sb-F Sb-Cl Sb-Br Sb-I Sb-Sb
402 248 184 195 299.2

Ionization enthalpies /kJ mol-1

Number Enthalpy


This section gives some data for naturally occurring isotopes.
Nominal mass Accurate mass % natural abundance
121Sb120.9038212 (29)57.36 (8)
123Sb122.9042160 (24)42.64 (8)

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/Sb.html