manganese

American  

[mang-guh-nees, -neez] / ˈmæŋ gəˌnis, -ˌniz /

noun

Chemistry.

1. a hard, brittle, grayish-white, metallic element, an oxide of which, MnO 2 manganese dioxide, is a valuable oxidizing agent: used chiefly as an alloying agent in steel to give it toughness. Mn; 54.938; 25; 7.2 at 20°C.

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manganese British  

/ ˈmæŋɡəˌniːz /

noun

1. a brittle greyish-white metallic element that exists in four allotropic forms, occurring principally in pyrolusite and rhodonite: used in making steel and ferromagnetic alloys. Symbol: Mn; atomic no: 25; atomic wt: 54.93805; valency: 1, 2, 3, 4, 6, or 7; relative density: 7.21–7.44; melting pt: 1246±3°C; boiling pt: 2062°C

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manganese Scientific  

/ măng′gə-nēz′ /

1. A grayish-white, hard, brittle metallic element that occurs in several different minerals and in nodules on the ocean floor. It is used to increase the hardness and strength of steel and other important alloys. Atomic number 25; atomic weight 54.9380; melting point 1,244°C; boiling point 1,962°C; specific gravity 7.21 to 7.44; valence 1, 2, 3, 4, 6, 7.

2. See Periodic Table

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Etymology

Origin of manganese

1670–80; < French manganèse < Italian manganese, alteration of Medieval Latin magnesia magnesia

Example Sentences

See Examples For:

manganese

Researchers had long believed that many black paintings in the region were made entirely from iron and manganese oxides.

From Science Daily ● Jul. 28, 2026

Lithium, cobalt, nickel and manganese for batteries in vehicles, drones, grid storage and military electronics.

From The Wall Street Journal ● Jul. 14, 2026

The agreement aims to give Europe better access to these materials, most notably aluminium, lithium and manganese.

From Barron's ● Apr. 23, 2026

It views South32’s 3Q results as “a mixed set,” highlighting misses in copper, zinc and manganese production offset by better-than-expected aluminum output.

From The Wall Street Journal ● Apr. 22, 2026

Still other soil microbes perform various oxidations and reductions by which minerals such as iron, manganese, and sulfur are transformed and made available to plants.

From "Silent Spring" by Rachel Carson