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Zirconium - Zr General Information Discovery Zirconium was discovered by M.H. Klaproth in 1789 in Berlin, Germany, and isolated by J.J. Berzelius in 1824 in Stockholm, Sweden. Appearance Zirconium is a hard, lustrous, greyish-white metal. Source Zirconium occurs in about 30 mineral species, the major ones being baddeleyite and zircon, found in Brazil. It is produced commercially by reduction of the chloride with magnesium. Uses Zirconium has very low absorption for neutrons, and is therefore useful in nuclear energy applications. More than 90% of zirconium production is used in this field, as reactors use many metres of zirconium alloy tubing. Zirconium is exceptionally resistant to corrosion by most agents including sea water, acids and alkalis, and so is used extensively by the chemical industry where corrosive agents are in use. With niobium, zirconium is superconductive at low temperatures and is used to make superconductive magnets. Impure zirconium(IV) oxide is used for crucibles which will withstand heat shock, for furnace linings, and by the glass and ceramics industries. Biological Role Zirconium has no known biological role. It is non-toxic. General Information The solid metal will burn in air, but with difficulty. When finely divided, however, it ignites spontaneously. |
| Physical Information | |||
| Atomic Number | 40 | ||
| Relative Atomic Mass (12C=12.000) | 91.224 | ||
| Melting Point/K | 2125 | ||
| Boiling Point/K | 4650 | ||
| Density/kg m-3 | 6506 (293K) | ||
| Ground State Electron Configuration | [Kr]4d25s2 | ||
| Electron Affinity(M-M-)/kJ mol-1 | -43 |
| Key Isotopes | ||||||
| nuclide | 90Zr | 91Zr | 92Zr | 94Zr | 95Zr | |
| atomic mass | 89.90 | 90.91 | 91.90 | 93.91 | 94.91 | |
| natural abundance | 51.45% | 11.32% | 17.19% | 17.28% | 0% | |
| half-life | stable | stable | stable | stable | 65 days | |
| nuclide | 96Zr | 97Zr | ||||
| atomic mass | 95.91 | |||||
| natural abundance | 2.76% | 0% | ||||
| half-life | 3.6x1017 yrs | 17 h | ||||
| Other Information | ||
| Enthalpy of Fusion/kJ mol-1 | 23 | |
| Enthalpy of Vaporisation/kJ mol-1 | 566.7 | |
| Oxidation States | ||
| main | Zr+4 | |
| others | Zr0, Zr+1, Zr+2, Zr+3 | |
| Ionisation Energies/kJ mol-1 | ||
| M - M+ | 660 | |
| M+ - M2+ | 1267 | |
| M2+ - M3+ | 2218 | |
| M3+ - M4+ | 3313 | |
| M4+ - M5+ | 7860 | |
| M5+ - M6+ | 9500 | |
| M6+ - M7+ | 11200 | |
| M7+ - M8+ | 13800 | |
| M8+ - M9+ | 15700 | |
| M9+ - M10+ | 17500 | |
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