Periodic Table


Atomic number: 75
Atomic weight: 186.207
Symbol: Re
Group number: 7
Electronic configuration: [Xe].4f14.5d5.6s2


Rhenium is silvery white with a metallic lustre; its density is exceeded only by that of platinum, iridium, and osmium, and its melting point is exceeded only by that of tungsten and carbon. It has other useful properties. It is expensive but useful as a trace alloying agent.

General information

Discoveror: Walter Noddack, Ida Tacke, Otto Berg
Date discovered: 1925
Discovered at: Germany
Meaning of name: From the Greek word "Rhenus" meaning river "Rhine"

Physical data

Standard state: solid at 298 K
Colour: greyish white
Density of solid at ambient temperature/kg m-3: 21020
Molar volume/cm3: 8.86

Radii /pm

Atomic: 188
Covalent (single bond):
Pauling radius for the ion [Re]-: no data

Valence shell orbital radius maxima (Rmax)
orbital s p d f
radius160.0no data73.921.9


Both values are quoted on the Pauling scale.

Pauling: 1.9
Allred Rochow: 1.46

Crystal Structure

structure: hcp (hexagonal close-packed)

The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.


Temperatures (/K)

melting point: 3459
boiling point: 5869

Enthalpies /kJ mol-1

fusion: 34.0
vaporization: 706

single bond enthalpies:
Re-F Re-Cl Re-Br Re-I Re-Re
no data no data no data no data no data

Ionization enthalpies /kJ mol-1

Number Enthalpy


This section gives some data for naturally occurring isotopes.
Nominal mass Accurate mass % natural abundance
185Re184.952951 (3)37.40 (2)
187Re186.955744 (3)62.60 (2)

Further Information

Copyright 1997 Mark Winter
Department of Chemistry at the University of Sheffield, Sheffield S3 7HF, England.

The current version of this document is at http://www.shef.ac.uk/~chem/web-elements-I/Re.html