Rhenium (Re)

Silvery-grayish

Rhenium is one of the rarest elements in Earth's crust and is used in jet engine turbine blades, and with a half-filled 5d⁵ shell, rhenium has the third-highest melting point (3459 K) and the highest boiling point (5869 K) of any metal. Rhenium additions to superalloys enable jet engines to operate at higher temperatures.

Key metrics

Density21.02g/cm³

Melting point3,459K

Boiling point5,869K

Electronegativity1.9Pauling

Discovery

1925discovered

Discovered by: Walter Noddack
Reactivity profile: Very high melting point
Reactivity: Low
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[Xe]}\; \textcolor{#a855f7}{4_{f}^{14}}\; \textcolor{#22c55e}{5_{d}^{5}}\; \textcolor{#ef4444}{6_{s}^{2}}

[Xe] 4f14 5d5 6s2

Wave function

\Psi_{\text{Re}} \approx \frac{1}{\sqrt{75!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{75}(\mathbf{r}_{75}) \right|

Probability density $|\Psi|^2$ across the Re valence shell.

Crystal structure

Hexagonal Close-Packed

Lattice constantsa 1.00 · b 1.00 · c 1.63

Cell anglesα 90° · β 90° · γ 120°

Coordination number12

Atoms per cell2

Atomic packing factor0.74

Physical properties

Atomic radius: 137 pm
Ionization energy: 760 kJ/mol
Electron affinity: 15 kJ/mol
Crystal structure: Hexagonal close-packed (hcp)

Oxidation states

-1+2+4+6+7

Acid/base

Basic

Strongly acidicStrongly basic

State at 25 °CSolid

3459 K5869 K298 K

Emission spectrum

3 transitions

380450500550600650700780

VioletBlueGreenYellowRed

451.8nmRe IBlue70%

488.6nmRe I (blue)Blue100%

527.6nmRe I (green)Green40%

Dominant line 488.6 nmRange 452–528 nmTransitions 3