|
General |
Name, Symbol, Number | Tin, Sn, 50 |
Chemical series | True metals[?] |
Group, Period, Block | 14 (IVA)[?], 5 , p |
Density, Hardness | 7310 kg/m3, 1.5 |
Appearance | silvery lustrous gray |
Atomic Properties |
Atomic weight | 118.710 amu |
Atomic radius (calc.) | 145 (145) pm |
Covalent radius | 141 pm |
van der Waals radius | 217 pm |
Electron configuration | [Kr]4d10 5s2 5p2 |
e- 's per energy level | 2, 8, 18, 18, 4 |
Oxidation states (Oxide) | 4,2 (amphoteric) |
Crystal structure | Tetragonal |
Physical Properties |
State of matter | Solid |
Melting point | 505.08 K (449.47 °F) |
Boiling point | 2875 K (4716 °F) |
Molar volume | 16.29 ×10-3 m3/mol |
Heat of vaporization | 295.8 kJ/mol |
Heat of fusion | 7.029 kJ/mol |
Vapor pressure | 5.78 E-21 Pa at 505 K |
Speed of sound | 2500 m/s at 293.15 K |
Miscellaneous |
Electronegativity | 1.96 (Pauling scale) |
Specific heat capacity | 228 J/(kg*K) |
Electrical conductivity | 9.17 106/m ohm |
Thermal conductivity | 66.6 W/(m*K) |
1st ionization potential | 708.6 kJ/mol |
2nd ionization potential | 1411.8 kJ/mol |
3rd ionization potential | 2943.0 kJ/mol |
4th ionization potential | 3930.3 kJ/mol |
5th ionization potential | 7456 kJ/mol |
Most Stable Isotopes |
iso | NA | half-life | DM | DE MeV | DP |
112Sn | 0.97% | Sn is stable with 62 neutrons |
114Sn | 0.65% | Sn is stable with 64 neutrons |
115Sn | 0.34% | Sn is stable with 65 neutrons |
116Sn | 14.54% | Sn is stable with 66 neutrons |
117Sn | 7.68% | Sn is stable with 67 neutrons |
118Sn | 24.23% | Sn is stable with 68 neutrons |
119Sn | 8.59% | Sn is stable with 69 neutrons |
120Sn | 32.59% | Sn is stable with 70 neutrons |
meta state 0.006 MeV | 55 y | IT[?] Beta- | 0.006 0.394 | 121Sb |
122Sn | 4.63% | Sn is stable with 72 neutrons |
124Sn | 5.79% | Sn is stable with 74 neutrons |
126Sn | {syn.} | ~1 E5 y | Beta- | 0.380 | 126Sb |
|
SI units & STP are used except where noted. |
Tin is a
chemical element in the
periodic table that has the symbol Sn and
atomic number 50. This silvery, malleable
true metal[?] that is not easily
oxidized in air and resists
corrosion is found in many
alloys and is used to coat other metals to prevent corrosion. Tin is obtained chiefly from the
mineral cassiterite[?] where it occurs as an
oxide.
Tin is a malleable, ductile, highly
crystalline, silvery-
white metal whose crystal structure causes a "tin cry" when a bar of tin is bent (caused by crystals breaking). This metal resists corrosion from
distilled sea and soft
tap water, but can be attacked by strong
acids,
alkalis, and by acid
salts. Tin acts as a
catalyst when
oxygen is in solution and helps accelerate chemical attack.
Tin forms Sn2 is when it is heated in the presence of air. Sn2, in turn, is feebly acidic and forms stannate (tin) salts with basic oxides. Tin can be highly polished and is used as a protective coat for other metals in order to prevent corrosion or other chemical action. This metal combines directly with chlorine and oxygen and displaces hydrogen from dilute acids. Tin is malleable at ordinary temperatures but is brittle when it is heated.
Solid tin has two allotropes at normal pressure. At low temperatures it exists as
gray or alpha tin, which has a cubic
crystal structure similar to
silicon and
germanium. When warmed above that 13.2 °
C it changes into
white or beta tin, which is metallic and has a tetragonal structure. It slowly changes back to the gray form when cooled, which is called the
tin pest or
tin disease. However, this transformation is affected by impurities such as
aluminum and
zinc and can be prevented from occurring through the addition of
antimony or
bismuth.
Tin bonds readily to
iron, and has been used for coating
lead or zinc and
steel to prevent
corrosion. Tin-plated
steel containers are widely used for
food preservation, and this forms a large part of the market for metallic tin. Other uses;
- Some important tin alloys are; bronze, bell metal[?], Babbitt metal[?], die casting[?] alloy, pewter, phosphor bronze[?], soft solder, and White metal.
- The most important salt formed is tin chloride, which has found use as a reducing agent and as a mordant[?] in the calico printing[?] process. Electrically conductive coatings are produced when tin salts are sprayed onto glass. These coatings have been used in panel lighting and in the production of frost-free windshields.
- Window glass is most often made via floating molten glass on top of molten tin (float glass) in order to make a flat surface (this is called the Pilkington process[?]).
- Tin is also used in solders for joining pipes or electrical/electronic circuits, in bearing alloys, in glass-making, and in a wide range of tin chemical applications.
Crystalline tin-niobium alloy is superconductive at very low temperatures and has been studied for use in the production of superconductive magnets[?] that can generate very strong magnetic field strengths while using very little power. These magnets, which are made of tin-niobium wire, weigh only a couple of kilograms and can make magnetic fields using power from a small battery that are comparable to those made by a 100 ton electromagnet using a large power supply.
Tin (
anglo-Saxon,
tin,
Latin stannum) is one of the earliest metals known and was used as a component of
bronze from antiquity. Because of its hardening effect on
copper, tin was used in bronze implements as early as
3,500 BC[?]. A thriving tin trade existed in Classical times between the mines in
Cornwall and the civilizations of the
Mediterranean. However the pure metal was not used until about
600 BC.
About 35 countries
mine tin throughout the world. Nearly every continent has an important tin-mining country. Tin is produced by reducing the
ore with
coal in a
reverberatory furnace[?]. This metal is a relatively scarce element with an abundance in the
earth's crust of about 2
ppm, compared with 94 ppm for zinc, 63 ppm for copper, and 12 ppm for lead. Most of the world's tin is produced from
placer[?] deposits; at least one-half comes from
Southeast Asia. The only
mineral of commercial importance as a source of tin is
cassiterite[?] (Sn
O2), although small quantities of tin are recovered from complex
sulfides[?] such as
stanite[?],
cylindrite[?],
frankeite[?],
canfieldite[?], and
teallite[?]. Secondary, or scrap, tin is also an important source of the tin.
Ordinary tin is made of nine stable
isotopes and there are 18 unstable isotopes in addition to this that are also known.
The small amount of tin that is found in canned foods is not harmful to humans. Tri
alkyl[?] and tri
aryl[?] tin compounds are
biocides and need to be handled with care.
See also: International Tin Council, tinned[?]