ruthenium

American  

[roo-thee-nee-uhm, -theen-yuhm] / ruˈθi ni əm, -ˈθin yəm /

noun

Chemistry.

1. a steel-gray, rare metallic element, belonging to the platinum group of metals. Ru; 101.07; 44; 12.2 at 20°C.

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ruthenium British  

/ ruːˈθiːnɪəm /

noun

1. a hard brittle white element of the platinum metal group. It occurs free with other platinum metals in pentlandite and other ores and is used to harden platinum and palladium. Symbol: Ru; atomic no: 44; atomic wt: 101.07; valency: 0–8; relative density: 12.41; melting pt: 2334°C; boiling pt: 4150°C

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ruthenium Scientific  

/ ro̅o̅-thē′nē-əm /

1. A rare, silvery-gray metallic element that is hard, brittle, and very resistant to corrosion. It is used to harden alloys of platinum and palladium for jewelry and electrical contacts. Atomic number 44; atomic weight 101.07; melting point 2,310°C; boiling point 3,900°C; specific gravity 12.41; valence 0, 1, 2, 3, 4, 5, 6, 7, 8.

2. See Periodic Table

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Etymology

Origin of ruthenium

1840–50; < New Latin, named after Ruthenia (from the fact that it was first found in ore from the region); see -ium

Example Sentences

The researchers synthesized 17 carefully designed ruthenium complexes and studied how small changes in molecular shape and the surrounding ionic environment influence electron behavior.

From Science Daily • Jan. 3, 2026

By adjusting the ligands and ions arranged around the ruthenium molecules, they demonstrated that a single device can display many different dynamic responses.

From Science Daily • Jan. 3, 2026

Manganese is more than 100,000 times more common on Earth than ruthenium, yet it has rarely been used successfully in photochemical systems.

From Science Daily • Nov. 26, 2025

Among these, ruthenium -- a platinum group metal -- has emerged as an important and commonly used catalyst.

From Science Daily • Apr. 8, 2024

The lower ovoids in ruthenium are identical in composition, with those of iron, cobalt and nickel and may be studied under Iron.

From Occult Chemistry Clairvoyant Observations on the Chemical Elements by Sinnett, A. P.