There are ten stable isotopes of tin, mainly those of masses 120, 118 and 116.
Tin exists in the oxidation states 0, + II and + IV. At room temperature the
simple tin body is a metallic solid.
Tin has been known since antiquity, where it was used to protect dishes from
oxidation and to prepare bronze. It is still used for this purpose, and for
soldering. This element is not very toxic. Rare in its native state, tin is
essentially extracted from a mineral called cassiterite where it is found in the
form of SnO2 oxide.
It is a silver-gray metal, malleable, moderately ductile at room temperature. It
is highly crystallized and the deformation of a tin plate produces noise; it is
said that the tin ¡°shouts¡± or ¡°cries¡± (twinning phenomenon).
It resists corrosion by seawater and freshwater, but can be attacked by strong
acids. This resistance is kinetic in nature since the normal potential of the
couple Sn2 + Sn = -0.136 V. It is therefore thermodynamically attacked by water,
and of course by oxygen.
Allotropic varieties
Main articles: Tin plague and Stanene.
At atmospheric pressure, pure tin has three allotropic varieties (it can exist
in three crystalline forms). Between 13 ¡ã C and 162 ¡ã C, the tin has a
tetragonal structure ({\ displaystyle \ beta} \ beta form), it is white tin,
with density 7.28 g cm − 3. Above 162 ¡ã C, we find the orthorhombic structure
(form {\ displaystyle \ gamma} \ gamma), brittle, which can be sprayed with a
mortar. Below 13 ¡ã C, white tin is slowly transformed into gray tin, of diamond
structure ({\ displaystyle \ alpha} \ alpha form), with density 5.75 g cm −3.
This transformation and the accompanying change in density affect the mechanical
strength of the material. Below −50 ¡ã C, the transformation is rapid and the tin
becomes powdery (falls to dust). It is the "tin plague" ("tin leprosy" when the
phenomenon remains superficial). This phenomenon "is described during the
Russian campaign by the soldiers of Napoleon, well placed to make this
observation, their pants buttons were in pewter".
By controlled deposition of tin in the gas phase on a solid substrate, it is
possible to form a monolayer of tin atoms of hexagonal structure: stanene,
similar to graphene. Stanene is a two-dimensional topological insulator.
Isotopes
Main article: Isotopes of tin.
Tin has 39 known isotopes, with mass numbers varying from 99 to 137, and 32
nuclear isomers. Among them, 10 are stable (three are potentially radioactive,
but no decay has yet been observed), which makes tin the element with the most
stable isotopes, followed by xenon. It is very likely that this property has
something to do with the fact that tin has 50 protons, a magic number.
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copper aluminum lead Zinc tin nickel iron
magnesium bismuth manganese chromium cobalt titanium
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