All practice pages/Interatomic theory/Elements

44Ru101.07

Element 44, a transition metal

Ruthenium

A hard platinum-group metal named for Russia, found in hard drives, electrical contacts and Nobel Prize-winning catalysts.

At a glance

Symbol
Ru
Atomic number
44
Average atomic mass
101.07
Group
8
Period
5
Family
transition metal
Electron configuration
[Kr] 4d⁷ 5s¹
Electronegativity
2.20
Common ions
+3 and +4 are most common; +8 in the volatile oxide RuO₄

On the table

Periodic table with Ruthenium highlighted123456789101112131415161718123456757-7189-103HHeLiBeBCNOFNeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaCePrNdPmSmEuGdTbDyHoErTmYbLuHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcThPaUNpPuAmCmBkCfEsFmMdNoLrRfDbSgBhHsMtDsRgCnNhFlMcLvTsOg

Period 5, group 8. The other transition metals are tinted, and every cell opens its own article.

Electrons and bonding

Like other transition metals, ruthenium loses its outer s electrons, and often some d electrons as well, to form positive ions, and it can form more than one kind.

Properties

State at 25 °C
solid
What it looks like
hard, brittle, silvery-white metal
Melting point
2334 °C
Boiling point
4150 °C
Density
12.1 g/cm³

Where it is found

One of the rarest metals, found with platinum in ores from South Africa and Russia and recovered while refining platinum and nickel.

Discovery and name

Karl Ernst Claus isolated it in 1844 at Kazan University from the residue left after dissolving platinum ore from the Ural Mountains, and named it after Ruthenia, a Latin name for Russia.

What it is used for

Thin ruthenium layers in hard disk drives, electrical contacts and chip resistors; a hardener in platinum and palladium jewelry; catalysts, including the Grubbs catalysts recognized by the 2005 Nobel Prize in Chemistry; and light-absorbing dyes for some solar cells.

In compounds

RuO₂ruthenium dioxide, in chip resistorsRuO₄ruthenium tetroxide, a strong oxidizerRuCl₃ruthenium(III) chloride

Handle with care

Ruthenium tetroxide is volatile, toxic and can explode.