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Zinc - Zn General Information Discovery Zinc was known in India and China before 1500. Appearance Zinc is a bluish-white, lustrous metal. Source Zinc is found in several ores, the principal ones being zinc blende and calamine. Commercially, zinc is obtained from its ores by concentrating and roasting the ore, then reducing it to zinc thermally with carbon or by electrolysis. Uses Zinc is used in alloys such as brass, nickel silver and aluminium solder. Large quantities of zinc are used to produce die-castings which are important in the automobile, electrical and hardware industries. It is also used extensively to galvanise other metals such as iron to prevent rusting. Zinc oxide is widely used in the manufacture of very many products such as paints, rubber, cosmetics, pharmaceuticals, plastics, inks, soaps, batteries, textiles and electrical equipment. Zinc sulfide is used in making luminous dials and fluorescent lights. Biological Role Zinc is an essential trace element which is non-toxic but carcinogenic in excess. When freshly-formed zinc(II) oxide is inhaled a disorder called the "oxide shakes" or "zinc chills" can occur. General Information Zinc reacts with both acids and alkalis. It tarnishes in air. It is brittle at normal temperatures but malleable at 100-150°C. It is a fair conductor of electricity, and burns in air at high red heat with the evolution of white clouds of the oxide. |
| Physical Information | |||
| Atomic Number | 30 | ||
| Relative Atomic Mass (12C=12.000) | 65.39 | ||
| Melting Point/K | 692.7 | ||
| Boiling Point/K | 1180 | ||
| Density/kg m-3 | 7133 (293K) | ||
| Ground State Electron Configuration | [Ar]3d104s2 | ||
| Electron Affinity(M-M-)/kJ mol-1 | -9 |
| Key Isotopes | ||||||
| nuclide | 64Zn | 65Zn | 66Zn | 67Zn | 68Zn | |
| atomic mass | 63.929 | 64.926 | 65.926 | 66.927 | 67.925 | |
| natural abundance | 48.6% | 0% | 27.9% | 4.1% | 18.8% | |
| half-life | stable | 243.6 days | stable | stable | stable | |
| nuclide | 70Zn | |||||
| atomic mass | 69.925 | |||||
| natural abundance | 0.6% | |||||
| half-life | stable | |||||
| Other Information | ||
| Enthalpy of Fusion/kJ mol-1 | 6.67 | |
| Enthalpy of Vaporisation/kJ mol-1 | 114.2 | |
| Oxidation States | ||
| main | Zn+2 | |
| others | Zn+1 | |
| Ionisation Energies/kJ mol-1 | ||
| M - M+ | 906.4 | |
| M+ - M2+ | 1733.3 | |
| M2+ - M3+ | 3832.6 | |
| M3+ - M4+ | 5730 | |
| M4+ - M5+ | 7970 | |
| M5+ - M6+ | 10400 | |
| M6+ - M7+ | 12900 | |
| M7+ - M8+ | 16800 | |
| M8+ - M9+ | 19600 | |
| M9+ - M10+ | 23000 | |
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