molybdenum

American  

[muh-lib-duh-nuhm] / məˈlɪb də nəm /

noun

Chemistry.

1. a silver-white metallic element, used as an alloy with iron in making hard, high-speed cutting tools. Mo; 95.94; 42; 10.2.

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molybdenum British  

/ mɒˈlɪbdɪnəm /

noun

1. a very hard ductile silvery-white metallic element occurring principally in molybdenite: used mainly in alloys, esp to harden and strengthen steels. Symbol: Mo; atomic no: 42; atomic wt: 95.94; valency: 2–6; relative density: 10.22; melting pt: 2623°C; boiling pt: 4639°C

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molybdenum Scientific  

/ mə-lĭb′də-nəm /

1. A hard, silvery-white metallic element that resists corrosion and retains its strength at high temperatures. It is used to harden and toughen steel and to make high-temperature wiring. Molybdenum is an essential trace element in plant metabolism. Atomic number 42; atomic weight 95.96; melting point 2,623°C; boiling point 4,639°C; specific gravity 10.22 (at 20°C); valence 2, 3, 4, 5, 6.

2. See Periodic Table

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Etymology

Origin of molybdenum

First recorded in 1790–1800; from New Latin molybdēnum, alteration of earlier molybdēna “lead ore,” from Latin molybdaena, from Greek molýbdaina “galena,” equivalent to mólybd(os) “lead” + -aina a suffix indicating relationship or origin

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Example Sentences

See Examples For:

molybdenum

A metallic compound, molybdenum trioxide can be used to make tough, heat-resistant alloys used in armored vehicles or missile engines.

From The Wall Street Journal ● Nov. 3, 2026

The researchers then set out to confirm that the enzyme contained a molybdenum metallocofactor.

From Science Daily ● Sep. 19, 2026

After Mr. Trump returned to office, China imposed further export controls on tungsten, tellurium, bismuth, molybdenum, indium and seven medium and heavy rare earths, including dysprosium and terbium.

From The Wall Street Journal ● Sep. 8, 2026

The team also produced nanocrystals from several related nitride materials, including titanium nitride, which is used in medical implants; niobium nitride, an important industrial superconductor; and molybdenum nitride, which is commonly used as a catalyst.

From Science Daily ● Aug. 30, 2026

“He said that he wasn’t surprised, and when I asked him why, he said, ‘Well, now, you know molybdenum is a chemical element.

From "Silent To The Bone" by E.L. Konigsburg

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