Rhenium
transition metal · period 6 · group 7 · d-block
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table.
What the numbers say
At standard temperature and pressure Rhenium is a solid, sitting in period 6, group 7 of the d-block.
Its melting point of 3459 K (3186 °C) is the 3rd highest of the 110 elements with a measured value — one of the most refractory elements there is.
At 21.02 g/cm³ it is the 4th densest of 96 elements with a quoted density.
Pauling electronegativity is 1.9. Paired with oxygen (3.44) that is a difference of 1.54, which puts the bond polar covalent — oxides here tend to be semiconducting or refractory rather than salt-like.
In the solid state it takes a simple hexagonal structure — hexagonal packing offers few easy slip systems, so properties are anisotropic and formability is limited.
It is reported in 9 oxidation states (-3, -1, 1, 2, 3, 4, 5, 6, 7), which sets how many distinct compounds and phases it can form.
First identified in 1925.
Crystal structure
Solid Rhenium adopts a Simple Hexagonal arrangement, in the Hexagonal system — axes a = b ≠ c, angles α = β = 90°, γ = 120°. Symmetry controls the anisotropy of stiffness and thermal expansion, and the available slip systems set how far the metal deforms before it fractures.
Check it against computed structures
The structure search queries the Materials Project, OQMD and the Open Materials Database for computed crystal structures containing Re — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 8 · M 18 · N 32 · O 13 · P 2
Properties
| Atomic number | 75 |
|---|---|
| Atomic mass | 186.2071 u |
| Series | transition metal |
| Group | 7 |
| Period | 6 |
| Block | d-block |
| Phase at STP | Solid |
| Density | 21.02 g/cm³ |
| Melting point | 3459 K (3186 °C) |
| Boiling point | 5869 K (5596 °C) |
| Electronegativity (Pauling) | 1.9 |
| Electron configuration | [Xe] 4f¹⁴ 5d⁵ 6s² |
| Crystal structure | Simple Hexagonal |
| Oxidation states | -3,-1,1,2,3,4,5,6,7 |
| Discovered | 1925 |
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See Re in context with all 118 elements.
Working with rhenium in a real design?
Ask the materials chat how Re behaves in your alloy system, what it does to weldability, and which grades to look at — with the source of every number named.