Tin

Tin - Sn

CAS: 7440-31-5
Description: Very malleable, white metal
Classification: Other Metals
Date of Discovery: Known to the ancients
Discoverer: Unknown
Name Origin: Anglo-Saxon, tin
Symbol Origin: Latin stannum, "tin"

Atomic Number: 50
Number of Neutrons: 69
Atomic Mass: 118.710(7) amu
Melting Point: 231.928 °C
Boiling Point: 2602 °C
Density (293 K):
7.31 g/cm³ (white)
5.75 g/cm³ (gray)
Atomic volume: 16.3 cm³/mol
Electrical resistivity: 0.816 10^-6/cm

Thermal conductivity: 0.666 W/cmK
Enthalpy of atomization: 301.25 kJ/mol
Enthalpy of vaporization: 295.80 kJ/mol
Enthalpy of fusion: 7.029 kJ/mol
Specific heat capacity: 0.227 J/gK

Energy levels: 2-8-18-18-4
Electron configuration: [Kr]4d¹⁰5s²5p²
Crystal Structure: Tetragonal
Atomic radius: 1.72 Å
Covalent radius: 1.41 Å
Oxidation States: +2, +4
Electronegativity, Pauling: 1.96
Electron affinity: 1.112 eV
First ionization energy: 7.344 eV
2nd ionization energy: 14.632 eV
3rd ionization energy: 30.502 eV
Polarizability: 7.7 10^-24cm³

Isotope	Natural Abundance	Atomic Mass	Half-life	Decay Mode	Spin
¹⁰⁰Sn	99.9394	⁺
¹⁰¹Sn	100.9361	⁺
¹⁰²Sn	101.9243	⁺
¹⁰³Sn	102.9281	7 s	⁺
¹⁰⁴Sn	103.9232	21 s	⁺, EC
¹⁰⁵Sn	104.9214	28 s	⁺
¹⁰⁶Sn	105.91688	2.0 m	⁺; EC
¹⁰⁷Sn	106.9157	2.92 m	EC; ⁺
¹⁰⁸Sn	107.91196	10.3 m	⁺; EC	0+
¹⁰⁹Sn	108.91129	18.0 m	⁺; EC	7/2+
¹¹⁰Sn	109.90785	4.1 h	EC	0+
¹¹¹Sn	110.90774	35 m	⁺; EC	7/2+
¹¹²Sn	0.97(1)	111.904822	Stable	0+
^113mSn	21.4 m	IT; EC	7/2+
¹¹³Sn	112.905174	115.1 d	EC	1/2+
¹¹⁴Sn	0.65(1)	113.902783	Stable	0+
¹¹⁵Sn	0.34(1)	114.903347	Stable	1/2+
¹¹⁶Sn	14.54(1)	115.901745	Stable	0+
^117mSn	13.60 d	IT	11/2-
¹¹⁷Sn	7.68(7)	116.902955	Stable	1/2+
¹¹⁸Sn	24.22(11)	117.901608	Stable	0+
^119mSn	293 d	IT	11/2-
¹¹⁹Sn	8.59(4)	118.903311	Stable	1/2+
¹²⁰Sn	32.59(10)	119.902199	Stable	0+
^121mSn	55 y	IT; ^-	11/2-
¹²¹Sn	120.904239	1.128 d	^-	3/2+
¹²²Sn	4.63(3)	121.903441	Stable	0+
^123mSn	40.1 m	^-	3/2+
¹²³Sn	122.905723	129.2 d	^-	11/2-
¹²⁴Sn	5.79(5)	123.905275	Stable	0+
^125mSn	9.51 m	^-	3/2+
¹²⁵Sn	124.907785	9.63 d	^-	11/2-
¹²⁶Sn	125.90765	100000 y	^-	0+
^127mSn	4.15 m	^-	3/2+
¹²⁷Sn	126.91035	2.12 h	^-	11/2-
^128mSn	6.5 s	IT	(7-)
¹²⁸Sn	127.91054	59.1 m	^-	0+
^129mSn	6.9 m	^-	11/2-
¹²⁹Sn	128.9134	2.4 m	^-	3/2+
^130mSn	1.7 m	^-	(7-)
¹³⁰Sn	129.91386	3.7 m	^-	0+
^131mSn	1.02 m	^-	11/2-
¹³¹Sn	130.9169	39 s	^-	3/2+
¹³²Sn	131.91775	^-
¹³³Sn	132.9236	1.44 s	^-	7/2-
¹³⁴Sn	133.9278	1.04 s	^-
Known to the ancients. Tin is found chiefly in cassiterite (SnO₂) and stannine (Cu₂FeSnS₄). Most of the world's supply comes from Malaysia, Bolivia, China, Indonesia, Russia, Zaire, Thailand, and Nigeria. The U.S. produces almost none, although occurrences have been found in Alaska and Colorado. Tin is obtained by reducing the ore with coal in a reverberatory furnace. Ordinary tin is composed of ten stable isotopes; thirty five unstable isotopes and isomers are also known. Ordinary tin is a silver-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 at normal pressure. On warming, gray, or tin, with a cubic structure, changes at 13.2 °C into white, or 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 gray. This change is affected by impurities such as aluminum and zinc, and can be prevented by small additions of antimony or bismuth. This change from the alpha to beta form is called the tin pest. There are few if any uses for gray tin. Tin takes a high polish and is used to coat other metals to prevent corrosion or other chemical action. Such tin plate over steel is used in the so-called tin can for preserving food. Alloys of tin are very important. Soft solder (33%Sn:67%Pb), type metal, fusible metal, pewter, bronze (20%Sn:80%Cu), bell metal, Babbitt metal, White metal, die casting alloy, and phosphor bronze are some of the important alloys using tin. 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, which is feebly acid, forming stannate salts with basic oxides. The most important salt is the chloride (SnCl₂ · H₂0), which is used as a reducing agent and as a mordant in calico printing. Tin salts sprayed onto glass are used to produce electrically conductive coatings. These have been used for panel lighting and for frost-free windshields. Most window glass is now made by floating molten glass on molten tin (float glass) to produce a flat surface (Pilkington process). Stannous fluoride (SnF₂) is used in some toothpastes. Of recent interest is a crystalline tin-niobium alloy that is superconductive at very low temperatures. This promises to be important in the construction of superconductive magnets that generate enormous field strengths but use practically no power. Such magnets, made of tin-niobium wire, weigh but a few pounds and produce magnetic fields that, when started with a small battery, are comparable to that of a 100 ton electromagnet operated continuously with a large power supply. The small amount of tin found in canned foods is quite harmless. The agreed limit of tin content in U.S. foods is 300 mg/kg. The trialkyl and triaryl tin compounds are used as biocides and must be handled carefully. LINKS: International Tin Research Institute (ITRI Ltd) Tin Chemistry What is the most effective toothpaste? Return Sources for the information on this website include: Lide, David R., ed. CRC Handbook of Chemistry and Physics, 78th Ed., 1997-1998.

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