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Tin - Sn General Information Discovery Tin was known to ancient civilisations. Alloyed with copper it forms bronze - which gave its name to the Bronze Age. Appearance Tin is a silvery-white metal. It is soft, pliable and has a highly crystalline structure. Source Tin is found mainly in the ore cassiterite, which is found in Malaya, Bolivia, Indonesia, Thailand and Nigeria. It is obtained commercially by reducing the ore with coal in a reverberatory furnace. Uses Tin has many uses. It takes a high polish and is used to coat other metals to prevent corrosion, such as in tin cans which are made of tin-coated steel. Alloys of tin are important, such as soft solder, pewter, bronze and phosphor bronze. The most important tin salt used is tin(II) chloride which is used as a reducing agent and as a mordant. Tin salts sprayed onto glass are used to produce electrically conductive coatings. Most window glass is made by floating molten glass on molten tin to produce a flat surface. Recently, a tin-niobium alloy that is superconductive at very low temperatures has attracted interest. Biological Role Tin is non-toxic. Trialkyl and triaryl tin compounds are used as biocides and must be handled with care. General Information Tin is unreactive to water and oxygen, as it is protected by an oxide film. It reacts with acids and bases. When heated in air, tin forms tin(IV) oxide which is feebly acidic. When a tin bar is broken, a "tin cry" is heard due to the breaking of the tin crystals. Tin has two allotropic forms. On warming, grey tin, with a cubic structure, changes into white tin, the ordinary form of the metal. |
| Physical Information | |||
| Atomic Number | 50 | ||
| Relative Atomic Mass (12C=12.000) | 118.71 | ||
| Melting Point/K | 505 | ||
| Boiling Point/K | 2543 | ||
| Density/kg m-3 | 7310 (293K) | ||
| Ground State Electron Configuration | [Kr]4d105s25p2 | ||
| Electron Affinity(M-M-)/kJ mol-1 | -121 |
| Key Isotopes | ||||||
| nuclide | 112Sn | 113Sn | 114Sn | 115Sn | 116Sn | |
| atomic mass | 111.91 | 113.9 | 114.9 | 115.9 | ||
| natural abundance | 1% | 0% | 0.7% | 0.4% | 14.7% | |
| half-life | stable | 115 days | stable | stable | stable | |
| nuclide | 117Sn | 118Sn | 119Sn | 120Sn | 121Sn | |
| atomic mass | 116.9 | 117.9 | 118.9 | 119.9 | ||
| natural abundance | 7.7% | 24.3% | 8.6% | 32.4% | 0% | |
| half-life | stable | stable | stable | stable | 27.5 h | |
| nuclide | 122Sn | 124Sn | ||||
| atomic mass | 121.9 | 123.9 | ||||
| natural abundance | 4.6% | 5.6% | ||||
| half-life | stable | stable | ||||
| Other Information | ||
| Enthalpy of Fusion/kJ mol-1 | 7.2 | |
| Enthalpy of Vaporisation/kJ mol-1 | 296.2 | |
| Oxidation States | ||
| Sn+2, Sn+4 | ||
| Covalent Bonds /kJ mol-1 | ||
| Sn - H | 314 | |
| Sn - C | 225 | |
| Sn+2 - O | 557 | |
| Sn+4 - F | 322 | |
| Sn+4 - Cl | 315 | |
| Sn - Sn | 195 | |
| Ionisation Energies/kJ mol-1 | ||
| M - M+ | 708.6 | |
| M+ - M2+ | 1411.8 | |
| M2+ - M3+ | 2943 | |
| M3+ - M4+ | 3930.2 | |
| M4+ - M5+ | 6974 | |
| M5+ - M6+ | 9900 | |
| M6+ - M7+ | 12200 | |
| M7+ - M8+ | 14600 | |
| M8+ - M9+ | 17000 | |
| M9+ - M10+ | 20600 | |
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