Símbolo | Mo |
Número atómico | 42 |
Grupo | 6 (Familia del cromo) |
Período | 5 |
Bloque | d |
Clasificación | Metal de transición |
Apariencia | Gray metallic |
Color | Gris |
Número de protones | 42 p+ |
Número de neutrones | 54 n0 |
Número de electrones | 42 e- |
Fase en STP | Sólido |
Densidad | 10.28 g/cm3 |
Peso atómico | 95.951 u |
Punto de fusión | 2896 K 2622.85 °C 4753.13 °F |
Punto de ebullición | 4912 K 4638.85 °C 8381.93 °F |
Entalpía de vaporización | 590.4 kJ/mol |
Electronegatividad (Escala de Pauling) | 2.16 |
Afinidad electrónica | 72.1 kJ/mol |
Estado de oxidación | −4, −2, −1, 0, +1, +2, +3, +4, +5, +6 (a strongly acidic oxide) |
Energía de ionización |
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Descubrimiento | Carl Wilhelm Scheele (1778) |
Primer aislamiento | Peter Jacob Hjelm (1781) |
Descubrimiento de molibdeno Molybdenite—the principal ore from which molybdenum is now extracted—was previously known as molybdena. Molybdena was confused with and often utilized as though it were graphite. Like graphite, molybdenite can be used to blacken a surface or as a solid lubricant. Although (reportedly) molybdenum was deliberately alloyed with steel in one 14th-century Japanese sword (mfd. ca. 1330), that art was never employed widely and was later lost. In the West in 1754, Bengt Andersson Qvist examined a sample of molybdenite and determined that it did not contain lead and thus was not galena. By 1778 Swedish chemist Carl Wilhelm Scheele stated firmly that molybdena was (indeed) neither galena nor graphite. Instead, Scheele correctly proposed that molybdena was an ore of a distinct new element, named molybdenum for the mineral in which it resided, and from which it might be isolated. Peter Jacob Hjelm successfully isolated molybdenum using carbon and linseed oil in 1781. |