All practice pages/Interatomic theory/Elements

75Re186.21

Element 75, a transition metal

Rhenium

The last stable element to be discovered and one of the rarest, now working in the hottest parts of jet engines.

At a glance

Symbol
Re
Atomic number
75
Average atomic mass
186.21
Group
7
Period
6
Family
transition metal
Electron configuration
[Xe] 4f¹⁴ 5d⁵ 6s²
Electronegativity
1.90
Common ions
+7 in the perrhenate ion ReO₄⁻; also +4 and +6

On the table

Periodic table with Rhenium highlighted123456789101112131415161718123456757-7189-103HHeLiBeBCNOFNeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaCePrNdPmSmEuGdTbDyHoErTmYbLuHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcThPaUNpPuAmCmBkCfEsFmMdNoLrRfDbSgBhHsMtDsRgCnNhFlMcLvTsOg

Period 6, group 7. The other transition metals are tinted, and every cell opens its own article.

Electrons and bonding

Like other transition metals, rhenium 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
dense, silvery-white metal
Melting point
3186 °C
Boiling point
5596 °C
Density
20.8 g/cm³

Where it is found

One of the rarest elements in the crust. It is recovered from the molybdenite in copper ores, mainly in Chile and the United States.

Discovery and name

Walter Noddack, Ida Tacke and Otto Berg found it in Germany in 1925, detecting it by its X-ray spectrum in platinum ore and columbite, and named it after the Rhine. Ida Tacke, later Ida Noddack, was also the first to suggest, in 1934, that heavy nuclei could split, years before fission was discovered.

What it is used for

Nearly all goes into nickel superalloys for jet engine turbine blades, which must stay strong close to their melting point. Platinum-rhenium catalysts help refine high-octane gasoline, and rhenium makes thermocouples and filaments for mass spectrometers.

In compounds

Re₂O₇rhenium heptoxideNH₄ReO₄ammonium perrhenateReS₂rhenium disulfideReO₃rhenium trioxide, conducts like a metal