Short answers, pulled from the story.
Carl Wilhelm Scheele discovered molybdenum in 1778 by recognizing that the mineral molybdena was a distinct new element rather than galena or graphite. Peter Jacob Hjelm first isolated the metal in 1781 using carbon and linseed oil.
About 86 percent of molybdenum goes into metallurgy, especially steel alloys, stainless steels, tool steels, and superalloys. Its compounds also serve as lubricants, catalysts in petroleum hydrodesulfurization, pigments, and as the isotope molybdenum-99 used to generate technetium-99m for medical imaging.
Molybdenum takes its name from the Ancient Greek word molybdos, meaning lead, because its ores were sometimes confused with those of lead. The mineral molybdenite was long mistaken for both the lead ore galena and for graphite.
Molybdenum has a melting point of 2623 degrees Celsius, the sixth highest of the naturally occurring elements. Only tantalum, osmium, rhenium, tungsten, and carbon have higher melting points.
Molybdenum is essential because it sits inside the most common nitrogenases, the bacterial catalysts responsible for biological nitrogen fixation. At least 50 molybdenum-containing enzymes are known across bacteria, plants, and animals, and it is an essential trace element for humans.
World production of molybdenum reached 250,000 tonnes in 2011, with China the largest producer at 94,000 tonnes, followed by the United States, Chile, Peru, and Mexico. The main commercial source is the ore molybdenite, often recovered as a byproduct of copper mining.