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| Technetium | Technétium | Tehnecij | Tecneto | Technetium | ||||||||||||||||||||
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Tc Technetium |
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- Technetium was discovered by Carlo Perrier and Emilio Segre (Italy) in 1937. The origin of the name comes from the Greek word technikos meaning artificial. It is silvery-grey metal. Resists oxidation but tarnishes in moist air and burns in high oxygen environment. First synthetically produced element. Radioactive.
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TRANSITION ELEMENT: MANGANESE GROUP | |
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| Relative atomic mass: | [98] | Electronic configuration: | [Kr] 4d6 5s1 |
| Formal oxidation number: | +4 +6 +7 | Electronegativities: | 2.1 |
| Thermal conductivity: | 50.6 W m-1 K-1 | Electrical resistivity (20 °C): | 16.9 μΩcm |
| Atomic radius: | 135.2 pm | Standard state (20 °C): | solid |
| Density (g dm-3): | 11500 (est., 293 K) | Molar volume (cm3 mol-1): | 8.52 (est., 293 K) |
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THERMAL PROPERTIES | |
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| Melting point: | 2157 °C | Heat of fusion: | 23.81 kJ mol-1 |
| Boiling point: | 4265 °C | Heat of vaporization: | 585.22 kJ mol-1 |
| Critical temperature: | 11227 °C | Heat of atomization: | 678 kJ mol-1 |
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IONIZATION ENERGIES AND ABUNDANCE | |
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| 1st ionization energy: | 702.42 kJ mol-1 | Abundance of element (air): | - ppm |
| 2nd ionization energy: | 1472.38 kJ mol-1 | Abundance of element (Earth's crust): | - ppm |
| 3rd ionization energy: | 2850.20 kJ mol-1 | Abundance of element (oceans): | - ppm |
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ISOTOPES | |
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Isotopes | Relative atomic mass | Abundance (%) |
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98Tc | 97.907216(4) | * |
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99Tc | 98.906255(2) | * |
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MINERALS AND USES | |
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- Technetium is made first by bombarding molybdenum with deuterons (heavy hydrogen) in a cyclotron. Added to iron in quantities as low as 55 part-per-million transforms the iron into a corrosion-resistant alloy.
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REDUCTION POTENTIALS | |
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Balanced half-reaction | Eo / V | Annotation |
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