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    Molybdenum (from the ancient Greek μόλυβδος / molubdos meaning lead) does not exist in the native state. Its natural compounds were confused until the eighteenth century with compounds of other elements such as carbon or lead.

In 1778 Carl Wilhelm Scheele successfully separated molybdenum from graphite and lead, and isolated molybdenum oxide from molybdenite.

In 1782 Peter Jacob Hjelm obtained an impure metal by reducing molybdenum oxide by carbon.

Until the end of the 19th century, molybdenum was used very little outside laboratories. When the French steelmaker Schneider noticed the properties of molybdenum steel alloys, he used them in the production of shields.

During the First World War, the Allies heard that the German artillery piece called "Grosse Bertha" contained molybdenum as an essential component of its steel. The information was false, but the study of the influence of this metal on the properties of steel was launched6.

Molybdenum is a transition metal. Pure metal has a metallic white appearance and is very hard. It has often been confused with graphite and galena ore. It has a high modulus of elasticity and only tungsten and tantalum, more readily available metals, have higher melting points.

It is a valid alloying agent because it contributes to the hardenability and hardness of quenched and tempered steels. It also improves the strength of steel at high temperatures. Molybdenum is used in alloys, electrodes and catalysts.
Molybdenum has 33 known isotopes, with a mass number varying between 83 and 115, and 8 nuclear isomers. Among these isotopes, six stable, 92Mo, 94Mo, 95Mo, 96Mo, 97Mo and 98Mo, and constitute with a primordial radionuclide (half-life of 1 × 1019 years), 100Mo, all of the molybdenum naturally present, the most abundant being 98MB (24.14%).
All stable isotopes are however theoretically capable of spontaneous fission, although the latter has not been observed in any of the cases. Similarly, 92Mo and 98Mo are suspected of being weakly radioactive, disintegrating by double beta beta emission, in 92Zr and 98Ru respectively with half-lives greater than 1.9 × 1020 years and 1 × 1014 years [Doubtful information], but again, such decays have never been observed before. Molybdenum is assigned a standard atomic mass of 95.95 (1) u7.



  

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