Periodic Table


Atomic number: 50
Atomic weight: 118.710
Symbol: Sn
Group number: 14
Electronic configuration: [Kr].4d10.5s2.5p2


Ordinary tin is a silvery-white metal, is malleable, somewhat ductile, and has a highly crystalline structure. Due to the breaking of these crystals, a "tin cry" is heard when a bar is bent. The element has two allotropic forms. On warming, grey, or a-tin, with a cubic structure, changes at 13.2°C into white, or b-tin, the ordinary form of the metal. White tin has a tetragonal structure. When tin is cooled below 13.2°C, it changes slowly from white to grey. This change is affected by impurities such as aluminium and zinc, and can be prevented by small additions of antimony or bismuth. The conversion was first noted as growths on organ pipes in European cathedrals, where it was thought to be the devils work. This conversion was also speculated to be caused microorganisms and was called "tin plague" or "tin disease".

Tin resists distilled, sea, and soft tap water, but is attacked by strong acids, alkalis, and acid salts. Oxygen in solution accelerates the attack. When heated in air, tin forms SnO2. It is, or was, used to plate steel, making "tin cans". Tin is used as one component in bell metals.

General information

Discoveror: Known since ancient times
Date discovered:
Discovered at: not known
Meaning of name: From the Anglo-Saxon word "tin" (the origin of the symbol Sn comes from the Latin word "stannum" meaning "tin")

Physical data

Standard state: solid at 298 K
Colour: silvery lustrous grey
Density of solid at ambient temperature/kg m-3: 7310
Molar volume/cm3: 16.29

Radii /pm

Atomic: 145
Covalent (single bond):
Pauling radius for the ion [Sn]-: 370

Valence shell orbital radius maxima (Rmax)
orbital s p d f
radius113.9139.546.8no data


Both values are quoted on the Pauling scale.

Pauling: 1.88
Allred Rochow: 1.72

Crystal Structure

structure: tetragonal

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: 505.08
boiling point: 2875

Enthalpies /kJ mol-1

fusion: 7.0
vaporization: 293

single bond enthalpies:
Sn-F Sn-Cl Sn-Br Sn-I Sn-Sn
414 323 273 205 195.4

Ionization enthalpies /kJ mol-1

Number Enthalpy


This section gives some data for naturally occurring isotopes.
Nominal mass Accurate mass % natural abundance
112Sn111.904826 (5)0.97 (1)
114Sn113.902784 (4)0.65 (1)
115Sn114.903348 (3)0.36 (1)
116Sn115.901747 (3)14.53 (11)
117Sn116.902956 (3)7.68 (7)
118Sn117.901609 (3)24.22 (11)
119Sn118.903311 (3)8.58 (4)
120Sn119.9021991 (29)32.59 (10)
122Sn121.9034404 (30)4.63 (3)
124Sn123.9052743 (17)5.79 (5)

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/Sn.html